Multimodal imaging system, apparatus, and methods

ABSTRACT

In part, the invention relates to an image data collection system. The system can include an interferometer having a reference arm that includes a first optical fiber of length of L1 and a sample arm that includes a second optical fiber of length of L2 and a first rotary coupler configured to interface with an optical tomography imaging probe, wherein the rotary coupler is in optical communication with the sample arm. In one embodiment, L2 is greater than about 5 meters. The first optical fiber and the second optical fiber can both be disposed in a common protective sheath. In one embodiment, the system further includes an optical element configured to adjust the optical path length of the reference arm, wherein the optical element is in optical communication with the reference arm and wherein the optical element is transmissive or reflective.

CROSS REFERENCE TO PRIOR APPLICATIONS

This application is a continuation of U.S. patent application No.13/484,763 filed on May 31, 2012, which claims priority to and thebenefit of U.S. Provisional Patent Application No. 61/491,701, filed onMay 31, 2011, and U.S. Provisional Patent Application No. 61/555,663,filed on Nov. 4, 2011, the disclosures of which are herein incorporatedby reference in their entirety.

FIELD OF THE INVENTION

The invention relates generally to devices and methods suitable for usein the fields of medical treatment and diagnostics and more specificallyto devices and methods that support one or more modes of data collectionrelevant to cardiology.

BACKGROUND

Interventional cardiologists incorporate a variety of diagnostic toolsduring catheterization procedures in order to plan, guide, and assesstherapies. These tools typically include optical coherence tomography(OCT), intravascular ultrasound, (IVUS), fractional flow reserve (FFR),and angiography. Intravascular OCT, IVUS, and FFR are invasivecatheter-based systems that collect optical, ultrasound, and pressuredata, respectively, from inside blood vessels or with respect to asample of interest. Angiography is a noninvasive x-ray imaging methodthat collects data from outside the body during injection of aradio-opaque contrast fluid.

Early OCT, IVUS, and FFR systems were typically single-purpose andincorporated only one of the three modalities. Each independent systemwas typically configured as a portable cart. If more than one modalitywas to be used during an interventional procedure, this approach had thesignificant disadvantage of increasing clutter in the catheterizationlab and requiring time-consuming set-up procedures. More recently,diagnostic systems have begun to incorporate IVUS and FFR or OCT and FFRon the same console. “Integrated” IVUS and FFR systems have also beendeveloped, where control devices and catheter interface devices arelocated in the procedure room, while data acquisition devices arelocated remotely in a control room. Such dual-modality, integratedsystems reduce clutter and reduce the total cost for diagnosticequipment.

Unfortunately, existing integrated IVUS and FFR diagnostic systemssuffer from various limitations that reduce their utility. Onelimitation is that existing integrated IVUS and FFR systems do notincorporate OCT imaging. OCT provides order-of-magnitude improvements toimage resolution compared to IVUS. OCT also enables more accurate plaquecharacterization, quantitative lesion measurements, thrombus detection,visualization of stent malapposition and edge dissections, andassessment of stent coverage following implantation.

A second limitation is that existing integrated systems require adedicated set of data acquisition and processing equipment to supporteach procedure room. This increases the capital costs associated withequipping multiple procedure rooms with diagnostic systems, leading tohigher health care expenditures. This limitation is even more pronouncedwith OCT systems than with IVUS systems, since the optical andelectronic hardware required for OCT imaging is significantly moreexpensive than that required for IVUS imaging.

Accordingly, a need therefore exists for a multimodal system and relateddevices that address these limitations.

SUMMARY OF THE INVENTION

The invention relates to a multimodal diagnostic system for use ininterventional cardiology and other diagnostic fields. In oneembodiment, multimodal or multiple modes refers to a plurality of datacollection modalities. One aspect of the invention is a system thatincorporates at least two of the following modalities in a singlesystem: optical coherence tomography (OCT), intravascular ultrasound(IVUS), fractional flow reserve (FFR), and X-ray angiographymeasurements in a single system. A patient interface unit (PIU) canconnect to one or more catheters to collect OCT and IVUS imaging data.FFR data collection can also be performed using wired or wirelesspressure monitors and receivers. In one embodiment, angiographic x-rayimages can be collected, stored, and/or routed using a computer ornetwork. Such angiographic images can be co-registered with OCT and IVUSimages obtained using the multimodal system.

The system modules can be distributed between a main control room,multiple satellite control rooms, multiple procedure rooms or within aroom but remote from a common reference point such as a subject's orpatient's location or a support they are disposed upon during aprocedure. In one embodiment, a procedure room can be a catheterizationlab (or cath lab), for example. In this way, ease of use is increasedwhile hardware costs are decreased. In one embodiment, a probe, such asan OCT probe or an IVUS probe or an FFR probe is used in the procedureroom to measure a sample of interest in a patient. Various networktopologies, cable arrangements, and data routing techniques can be usedto facilitate the operation of a given multimodal system.

In one aspect, the invention relates to a data collection system foracquiring data with respect to a patient disposed on a support. Thesystem includes an imaging engine that includes an optical radiationsource; an interferometer that includes a reference arm that includes afirst optical fiber of length of L1 and a sample arm that includes asecond optical fiber of length of L2; a patient interface unitconfigured to interface with a data collection probe, wherein thepatient interface unit is in optical communication with the sample arm;and a display configured to display an image generated using opticalcoherence tomography data collected using the data collection probe,wherein the imaging engine is located remotely from the support, whereinthe patient interface unit and the display are located proximal to thesupport.

In one embodiment, L2 is greater than about 5 meters. In one embodiment,the system includes a dock in optical communication with the patientinterface unit. In one embodiment, the system further includes aprotective sheath, wherein a section of the reference arm and a sectionof the sample arm between the imaging engine and the dock are at leastpartially disposed within the protective sheath such that each sectionis exposed to substantially similar environmental conditions. In oneembodiment, a first section of the reference arm and a first section ofthe sample arm are at least partially disposed in the dock. In oneembodiment, the dock is configured to receive and hold the patientinterface unit. In one embodiment, the dock is configured to receivewireless data from the data collection probe, and further includes auser interface device that includes a touch screen, a selecting unitconfigured to select between the data collection probe and a pressuretransducer-based device, and a graphical user interface, the userinterface device configured to display images generated using image dataor a pressure data-based parameter and to receive user inputs. In oneembodiment, the patient interface unit is configured to receive anintravascular ultrasound imaging probe. In one embodiment, the datacollection probe is configured to collect the optical coherencetomography data and one or both of ultrasound data and pressure data.

In one embodiment, the system further includes a first converterconfigured to receive electrical ultrasound signals generated using thedata collection probe and convert the electrical ultrasound signals intooptical signals for transmission to a second converter. In oneembodiment, the system further includes a first converter configured toreceive electrical pressure signals generated using the data collectionprobe and convert the electrical pressure signals into optical signalsfor transmission to a second converter. In one embodiment, the systemfurther includes a third optical fiber disposed in the protectivesheath, the third optical fiber configured to transmit pressure data orultra sound data received from the data collection probe. In oneembodiment, the system further includes a digital communication fiber oran electrical wire disposed in the protective sheath.

In one aspect, the invention relates to an image data collection system.The system includes an interferometer includes a reference arm thatincludes a first optical fiber of length of L1 and a sample arm thatincludes a second optical fiber of length of L2; and a first rotarycoupler configured to interface with an optical tomography imagingprobe, wherein the rotary coupler is in optical communication with thesample arm and wherein L2 is greater than about 5 meters.

In one embodiment, the first optical fiber and the second optical fiberare both disposed in a common protective sheath. In one embodiment, thesystem further includes an optical element configured to adjust theoptical path length of the reference arm, wherein the optical element isin optical communication with the reference arm and wherein the opticalelement is transmissive or reflective. In one embodiment, the lengths L1and L2 and the disposition of the first optical fiber and the secondoptical fiber in the common protective sheath are configured tosubstantially reduce degradation of an image formed using data collectedby the optical tomography imaging probe. In one embodiment, the systemfurther includes an electrically conductive wire disposed within theprotective sheath. In one embodiment, the system further includes anultrasound system that includes an electrical to optical converterconfigured to receive an electrical signal that includes ultrasound dataand convert the electrical signal to an optical signal. In oneembodiment, the ultrasound system includes a third optical fiber oflength of L3, wherein the third optical fiber is configured to conductthe optical signal between a first location in which the firstinterferometer is positioned and a second location in which the rotarycoupler is positioned, the third optical fiber having a first end and asecond end. In one embodiment, the first interferometer is installed ina first room and the rotary coupler is disposed in a second room and thelength of the protective sheath is sized to optically couple the firstrotary coupler and the sample arm via the second optical fiber.

In one embodiment, the system further includes a server configured tocollect image data and a portable wireless control station that includesa display, and one or more input devices, wherein the portable controlstation is configured to control at least one of the server and imagedata collection by the optical tomography imaging probe. In oneembodiment, the system further includes a circulator and a reflective ortransmissive variable path length mirror in optical communication withthe reference arm and the circulator. In one embodiment, the systemfurther includes a fiber Bragg grating and a photodetector, wherein thereference arm is in optical communication with the fiber Bragg gratingand the photodetector. In one embodiment, the photodetector isconfigured to transmit a pulse for synchronizing ultrasound datacollection and OCT data collection in response to a received wavelengthfrom the fiber Bragg grating. In one embodiment, the common protectivesheath has a length greater than about 5 meters. In one embodiment, theserver includes a data acquisition device with two channels, wherein onechannel is configured to acquire data according to a variable frequencyexternal clock.

In one embodiment, the system further includes one or more switches; aserver; and one or more interface systems, each interface system incommunication with a respective switch, each interface system configuredto interface with the optical coherence tomography probe, a pressurewire or an ultrasound probe, wherein the server is configured to collectdata from each interface system. In one embodiment, the system furtherincludes an optical coupler having a first, second and third arm, thefirst arm of the optical coupler in optical communication with the oneor more switches; a mirror in optical communication with the second armof the optical coupler; and a circulator having a first, second andthird port, the first port being in optical communication with theoptical coupler, the second port in optical communication with a fiberBragg grating, and a third port in optical communication with aphotodetector, wherein the photodetector generates a trigger signal whena certain wavelength occurs in the optical signal from the one or moreswitches.

In one embodiment, the system further includes a user interface devicethat includes a touch screen, a selecting unit configured to selectbetween the optical tomography imaging probe and a pressuretransducer-based device, and a graphical user interface, the userinterface device configured to display images generated using image dataor a pressure data-based parameter and to receive user inputs. In oneembodiment, the user interface device is component of a mobile terminalin electrical or optical communication with a server configured toreceive data from the optical tomography imaging probe. In oneembodiment, each interface system includes an interface dock and aninterface unit, wherein the interface dock provides anoptical-electrical interface between the interface unit and the server.In one embodiment, the system further includes a variable path lengthair gap in optical communication with the reference arm. In oneembodiment, the system further includes a first wavelength divisionmultiplexing filter in optical communication with the first end of thethird optical fiber and a second wavelength division multiplexing filterin optical communication with the second end of the third optical fiber.In one embodiment, the first optical fiber, the second optical fiber,and the third optical fiber and a strength member are all disposed in acommon protective sheath.

In one aspect, the invention relates to an intravascular data collectionsystem. The system includes a computer that includes a digitizer havingone or more inputs to receive at least one of an optical coherencetomography probe generated signal or an ultrasound transducer generatedsignal; an imaging engine that includes a light source; a patientinterface unit that includes a rotary coupler; a first wireless pressuredata receiver configured to receive pressure wire data; a patientinterface dock that includes a reference optical element; and aninterferometer that includes a reference arm that includes a firstoptical fiber of length of L1 and a sample arm that includes a secondoptical fiber of length of L2, wherein the rotary coupler is in opticalcommunication with the sample arm, wherein the reference optical elementis in optical communication with the reference arm, wherein the lightsource is in optical communication with the sample arm. In oneembodiment, the first optical fiber and the second optical fiber areboth disposed in a common protective sheath. In one embodiment, L2 isgreater than about 5 meters. In one embodiment, the system furtherincludes an optical element configured to adjust the optical path lengthof the reference arm, wherein the optical element is in opticalcommunication with the reference arm and wherein the optical element istransmissive or reflective.

In one embodiment, the system further includes a variable path lengthair gap in optical communication with the reference arm. In oneembodiment, the system further includes a user interface device thatincludes a touch screen, a selecting unit configured to select imagedata collected using the sample arm, and a graphical user interface, theuser interface device configured to display images generated using imagedata, one or more FFR values generated using pressure wire data and toreceive user inputs. In one embodiment, the system further includes asecond wireless pressure data receiver configured to receive aorticpressure data. In one embodiment, the system further includes a matchingunit configured to match an interface unit with a stored interface unitidentity, wherein the interface unit is configured to wirelessly relaypressure wire data to the first pressure data receiver. In oneembodiment, the system further includes a selection unit configured toselect between one or more OCT procedure rooms or one or more interfaceunits based on a received control signal or selection rule.

In one aspect, the invention relates to a method for co-registeringangiographic image data with intravascular optical tomography data. Themethod includes providing an angiography system proximal to a supportconfigured to position a patient in a catheterization laboratory;providing an intravascular optical tomography system that includes animaging engine that includes an optical radiation source; aninterferometer that includes a reference arm that includes a firstoptical fiber of length of L1 and a sample arm that includes a secondoptical fiber of length of L2; a patient interface unit configured tointerface with an optical tomography imaging probe, wherein the patientinterface unit is in optical communication with the sample arm; acomputer configured to receive and process image data from the opticaltomography imaging probe and generate images; and a monitor fordisplaying the images, wherein the imaging engine and the computer arelocated remotely from the support and the patient interface unit andmonitor are located proximal to the support; simultaneously collectingangiography data and intravascular optical tomography data with respectto a vessel disposed in the patient; and co-registering the angiographydata and intravascular optical tomography data.

In one embodiment, the method further includes transmitting angiographydata from the angiography system to the intravascular optical tomographysystem. In one embodiment, the method further includes transmittingintravascular optical tomography data from the intravascular opticaltomography system to the angiography system. In one embodiment, theintravascular optical tomography data and angiography data arecommunicated to a third system for co-registration.

In one aspect, the invention relates to an image data collection systemfor acquiring a first set of images of a first patient disposed on afirst support in a first examination room and a second set of images ofa second patient disposed on a second support in a second examinationroom. The system includes an imaging engine that includes an opticalradiation source; a first reference arm that includes a first opticalfiber of length of L1; a first sample arm that includes a second opticalfiber of length of L2; a second reference arm that includes a thirdoptical fiber of length of L3; a second sample arm that includes afourth optical fiber of length of L4; an optical switch directingoptical radiation from the imaging engine to one of the first referenceand first sample arms or second reference and second sample arms;wherein the first reference arm and the first sample arm are in opticalcommunication with the imaging engine and a first patient interface unitin the first examination room; wherein the second reference arm and thesecond sample arm are in optical communication with the imaging engineand a second patient interface unit in the second examination room; acomputer configured to receive and process image data from the first andsecond sample arms and generate a first set of image and a second set ofimages; a first monitor for displaying the first set of images in thefirst examination room; a second monitor for displaying the second setof images in the second examination room; and wherein the imaging engineand the computer are located remotely from the first support and thesecond support, the first patient interface unit and first monitor arelocated proximal to the first support and the second patient interfaceunit and second monitor are located proximal to the support.

In one aspect, the invention relates to an image data collection system.The system includes a patient interface system that includes a sectionof a sample arm of an interferometer defining a first optical path,wherein one end of the first optical path is configured to receiveoptical coherence data received from a data collection probe; a firstconverter configured to receive electrical ultrasound data and convertthe electrical ultrasound data to an optical signal; and an opticaldevice defining a second optical path, the optical device in opticalcommunication with the first converter and configured to transmit theoptical signal to a second converter.

In one embodiment, the system further includes a patient interface unitdock that includes a housing, wherein the section of the sample arm ofthe interferometer, the first converter, and the optical device are atleast partially disposed within the housing; and a patient interfaceunit that includes a coupler in optical communication with and disposedbetween the section of the sample arm of the interferometer and the datacollection probe, a drive motor configured to rotate an optical fiberdisposed in the data collection probe, and a receiver configured toreceive ultrasound data generated using the data collection probe or anintravascular ultrasound probe. In one embodiment, the system furtherincludes an imaging engine that includes a light source; theinterferometer in optical communication with the light source; and thesecond converter. In one embodiment, the system further includes aserver that includes a data acquisition device in electricalcommunication with the second converter.

In one aspect, the invention relates to a method of generating anoptical coherence tomography image of a portion of a subject disposed ona support. The method includes transmitting light from a light source ata first location along a sample arm of an interferometer and a referencearm of the interferometer, the sample arm terminating at a secondlocation and the reference arm terminating at a third location, whereinthe distance between the first location and second location is greaterthan about 5 meters, the second location disposed within the subject andnear the portion of the subject; receiving light scattered from theportion of the subject at a data collection probe in opticalcommunication with the sample arm; receiving light scattered from areflector in optical communication with the sample arm; combining thelight received from the data collection probe and the light scatteredfrom the reflector to generate interference data; and generating theoptical coherence tomography image in response to the interference data.

In one embodiment, the third location is in a patient interface dock.The method can further include collecting ultrasound data with respectto the portion, the ultrasound data that includes a first electricalsignal. The method can further include converting the first electricalsignal to an optical signal and transmitting the optical signal along anoptical fiber to a fourth location. The method can further includeconverting the optical signal to a second electrical signal. The methodcan further include generating a second image of the portion of thesubject using the second electrical signal. The method can furtherinclude co-registering the optical coherence tomography image and thesecond image.

In one aspect, the invention relates to a multimodal imaging systemincluding an imaging engine having a plurality of switches; a server incommunication with the imaging engine; and a plurality of interfacesystems, each interface system in communication with respective ones ofthe plurality of switches; each interface system constructed to alsointerface with an OCT and ultrasound probe, and wherein the servercontrols the taking and processing of images from the OCT probes and theultrasound probes interfaced with the plurality of interface systems.

In one aspect, the invention relates to an image data collectionapparatus. The apparatus includes a plurality of switches; a server; anda plurality of interface systems, each interface system in communicationwith a respective one of the plurality of switches, each interfacesystem configured to interface in with at least one optical coherencetomography probe or ultrasound probe, wherein the server is configuredto collect data from each interface system.

In one embodiment, each switch of the plurality of switches is anoptical switch. Each of the plurality of interface systems can beconnected to the switch by a respective optical cable. Each respectiveoptical cable of the plurality of optical cables can be of a lengthsufficient to permit each of the plurality of interface systems to belocated in a different room. The server can be in electroniccommunication with an angiography system.

The server can be configured and/or programmed to display co-registeredoptical coherence tomography, ultrasound and angiographic images. Theimaging engine can include a Mach-Zehnder interferometer (MZI). The MZIcan be configured to generate a clock signal. The apparatus can includea delay device in communication with the Mach-Zehnder interferometer.The delay device can be configured to delay the clock signal to assurealignment between the clock signals and digitized interference signals.The delay device can be an electronic delay device or an optical delaydevice. In one embodiment, intervals between the rising or falling edgesof sequential clock signals are varied according to a user-selecteddelay to compensate for residual dispersion in the optical coherencetomography signals.

Each interface system can include an interface dock and an interfaceunit. An interface dock can include or provide an optical-electricalinterface between the interface unit, the server and the imaging engine.As part of this interface a converter can be included. The converter canbe used to transform ultrasound data from an electrical signal to anoptical signal. The interface dock can include a reflective mirror inoptical communication with the reference arm of a Michelsoninterferometer. The interface dock can include a trigger device. Thetrigger device can include an optical coupler having a first, second andthird arm, the first arm of the optical coupler in optical communicationwith one of the plurality of switches; a mirror in optical communicationwith the second arm of the optical coupler; and a circulator. In oneembodiment, the circulator has a first, second and third port, the firstport being in optical communication with the optical coupler, the secondport in optical communication with a fiber Bragg grating, and a thirdport in optical communication with a photodetector. The photodetectorcan be configured to generate a trigger signal when a certain wavelengthoccurs in the optical signal from the one of the plurality of switches.In one embodiment, the trigger signal initiates the generation of anultrasound pulse synchronously with illumination by a sample light froma sample arm of an interferometer.

The server can include a data acquisition device or component, such as adigitizer, with two channels wherein at least one channel is configuredto acquire data according to a variable frequency external clock;wherein one channel is configured to acquire optical coherencetomography data; and wherein a second channel is configured to acquireultrasound data. In one embodiment, the optical coherence tomographychannel is sampled in response to a time-varying external clock signal.In one embodiment, the ultrasound channel is sampled in response tofixed clock signal. In one embodiment, the ultrasound channel isacquired at a line rate that differs from the line rate of the opticalcoherence tomography channel by a factor that ranges from about 1 toabout 0.0625.

The apparatus can include a first optical coupler; a first opticalcirculator having a first port in optical communication with the opticalcoupler, a second port in communication with a variable path lengthmirror, a third port in optical communication with a first switch of theplurality of switches, and a fourth port in optical communication with apolarization controller; a second optical circulator having a first portin optical communication with the first optical coupler, a second portin optical communication with a mirror, a third port in opticalcommunication with a second switch of the plurality of switches, andhaving a fourth port; a balanced detector having a first input port anda second input port and having an output terminal; and a second opticalcoupler, having a first port in optical communication with thepolarization controller, a second port in optical communication with thefourth port of the second circulator, a third port in opticalcommunication with first input port of the balanced detector and afourth port in optical communication with the second input port of thebalanced detector.

The apparatus can include a first optical coupler; a first opticalcirculator having a first port in optical communication with the opticalcoupler, a second port in communication with a variable path lengthmirror, a third port in optical communication with a first switch of theplurality of switches, and a fourth port in optical communication with apolarization controller; a second optical circulator having a first portin optical communication with the first optical coupler, a second portin optical communication with a mirror, a third port in opticalcommunication with a second switch of the plurality of switches, andhaving a fourth port; a first balanced detector having a first inputport and a second input port and having an output terminal; a secondbalanced detector having a first input port and a second input port andhaving an output terminal and a second optical coupler; a third opticalcoupler; a fourth optical coupler; a fifth optical coupler; and a sixthoptical coupler; the second optical coupler in optical communicationwith the polarization controller, the third optical coupler, and thefifth optical coupler, the fifth optical coupler in opticalcommunication with the sixth optical coupler, the sixth optical couplerin optical communication with the second balanced detector, the thirdoptical coupler in optical communication with the first balanceddetector, the fourth optical coupler in optical communication with thethird optical coupler and the fourth port of the second opticalcirculator.

The apparatus can include a first optical coupler; a first opticalcirculator having a first port in optical communication with the opticalcoupler, a second port in communication with a variable path length airgap (VPLAG), the VPLAG in optical communication with a first switch ofthe plurality of switches, and a third port in optical communicationwith a polarization controller; a second optical circulator having afirst port in optical communication with the first optical coupler, asecond port in optical communication with a second switch of theplurality of switches, and having a third port; a balanced detectorhaving a first input port and a second input port and having an outputterminal; and a second optical coupler, having a first port in opticalcommunication with the polarization controller, a second port in opticalcommunication with the third port of the second circulator, a third portin optical communication with first input port of the balanced detectorand a fourth port in optical communication with the second input port ofthe balanced detector.

The apparatus can include a first optical coupler; a first opticalcirculator having a first port in optical communication with the opticalcoupler, a second port in communication with a variable path lengthmirror, a third port in optical communication with a first switch of theplurality of switches, and a fourth port in optical communication with apolarization controller; a second optical circulator having a first portin optical communication with the first optical coupler, a second portin optical communication with a mirror, a third port in opticalcommunication with a second switch of the plurality of switches, andhaving a fourth port; a balanced detector having a first input port anda second input port and having an output terminal; and a second opticalcoupler, having a first port in optical communication with thepolarization controller, a second port in optical communication with thefourth port of the second circulator, a third port in opticalcommunication with first input port of the balanced detector and afourth port in optical communication with the second input port of thebalanced detector.

In one aspect, the invention relates to a data collection system thatincludes an optical coherence tomography system that can include a firstinterferometer that can include a reference arm that can include a firstoptical fiber of length of L1, and a sample arm that includes a secondoptical fiber of length of L2, wherein the first optical fiber and thesecond optical fiber are both disposed in a common cable and a firstrotary coupler configured to interface with an optical tomographyimaging probe, wherein the rotary coupler is in optical communicationwith the sample arm. The first interferometer can be installed in afirst room and the rotary coupler is disposed in a second room and thecable is sized to optically couple the first rotary coupler and thesample arm via the second optical fiber of length L2. The first opticalfiber of length L1 can be in optical communication with a reflectivemirror. Additional interferometers can be used at the same or differentlocations relative to the first interferometer.

The optical coherence tomography system further can include an opticalswitch having a first port in optical communication with the sample armand a second port in optical communication with the first rotarycoupler. The optical coherence tomography system further can include acirculator and a reflective or transmissive variable path length mirrorin optical communication with the reference arm and the circulator. Theoptical coherence tomography system further can include a fiber Bragggrating and a photodetector, wherein the reference arm is in opticalcommunication with the fiber Bragg grating and the photodetector. In oneembodiment, the photodetector is configured to transmit a pulse forsynchronizing ultrasound data collection and OCT data collection inresponse to a received wavelength from the fiber Bragg grating.

The data collection system can further include an ultrasound system thatincludes an electrical to optical converter configured to receive anelectrical signal that includes ultrasound data and convert theelectrical signal to an optical signal. The ultrasound system caninclude an optical switch and a third optical fiber of length of L3,wherein the third optical fiber conducts the optical signal between afirst room in which the interferometer is disposed and a second room inwhich the rotary coupler is disposed. The data collection system canfurther include a digitizer having a first channel and a second channel,wherein the first channel receives a signal from the optical coherencetomography system and the second channel receives a signal from theultrasound system.

In one embodiment, the optical coherence tomography data is digitizedaccording to a variable frequency clock and the ultrasound signal isdigitized according to a fixed frequency clock. The dock can include amirror in optical communication with a first switch of the plurality ofswitches and a first WDM filter in optical communication with both asecond switch of the plurality of switches and a second WDM filter,wherein the second WDM filter is in optical communication with thesecond switch of the plurality of switches. The data collection systemcan be configured such that L1 and L2 are greater than about 5 meters.The fibers associated with L1 and L2 can be in the same or locations.The interface dock can include at least one wireless receiver forreceiving intravascular pressure data.

In one aspect, the invention relates to an intravascular data collectionsystem that includes a first primary data collection element thatincludes a digitizer having one or more inputs to receive at least oneof an OCT related signal, a FFR related signal, and an ultrasoundrelated signal; a first supplemental data collection element thatincludes a probe that includes an optical fiber; a second supplementaldata collection element that includes a subset of a sample arm; anetwork having a first topology with a central node, a first auxiliarynode and a second auxiliary node connected by a first link and a secondlink respectively, wherein the first primary data collection element ispositioned at the central node and the first and second supplementaldata collection elements are disposed at the respective first and secondauxiliary nodes, wherein the auxiliary nodes are disposed a distance D1and D2 from the central node. Each link can include an optical fiber andan electrical conductor disposed in a common enclosure. At least onelink can include a portion of an arm of an interferometer. At least onelink can include a reference arm that includes a first optical fiber oflength of L1, and a sample arm that includes a second optical fiber oflength of L2, wherein the first optical fiber and the second opticalfiber are both disposed in protective sheath such as for example acommon cable or jacket or other covering.

In part, the invention relates to systems, methods and devices, such asinput devices, controllers and interfaces that improve the process ofinitiating a measuring procedure, such as an OCT, IVUS, or pressure-wirebased procedure and to provide procedures for configuring and installinga monitoring device that reduce error and setup time.

In part, the invention relates to systems, methods and devices, such asinput devices, controllers and interfaces that improve flexibility ofthe measurement equipment such that different desired measurement unitsquickly and easily can be connected and disconnected. Thus, a plug andplay configuration for an OCT system, a pressure wire system, otherimaging and pressure measuring modalities, and combinations thereof areembodiments of the invention.

In part, the invention relates to systems, methods and devices thatsupport graphical interfaces and displays, such as display screen-basedor touch screen based interfaces, and the displays themselves thatimprove and facilitate user interaction with a monitoring device orfacilitate mobile use or use from a remote location relative to a room,a catheter lab, or other location.

In one embodiment, the invention relates to a probe, which can include apressure or imaging probe, for monitoring, analysing, and displayingphysiological conditions related to pressure in a vessel such as bloodpressure. The device can include a pressure wire receiver unitconfigured to receive a wireless signal representing a measuredphysiological, or other, variable in the living body, an aortic bloodpressure receiver unit configured to receive, from at least one aorticpressure interface unit, a wireless signal including interface identityinformation required to identify the interface unit, and informationrepresenting measured aortic blood pressure, a signal processing elementor subsystem configured to calculate blood pressure related parameters,a touch screen configured to display information regarding selectableaortic pressure interface units and blood pressure related parameters,and to receive user input, an identifying unit configured to identifyinterface units based upon received interface identity information, apresentation unit configured to present, on the touch screen, theinterface unit(s) identified by the identifying unit, a selecting unitconfigured to select one of the presented interface units, and whereinthe aortic blood pressure receiver unit is configured to receive aorticpressure information from the selected aortic pressure interface unit.

According to another aspect, the invention also relates to an opticalcoherence tomography system that includes a probe, which can include apressure or imaging probe, wherein the system includes a displayconfigured to provide a graphical interface to a system operator or use.According to a further aspect, the invention relates to method forsetting up a probe.

In part, the invention relates to installing, configuring or otherwisesetting up a probe, which can include a pressure or imaging probe, formonitoring, analysing, and displaying physiological conditions relatedto blood pressure. The method includes receiving, from at least oneaortic pressure interface unit, a wireless signal including interfaceidentity information required to identify the interface unit; displayingon a touch screen information regarding selectable aortic pressureinterface units; identifying interface units based upon receivedinterface identity information; presenting the identified interfaceunit(s) on the touch screen; selecting one of the presented interfaceunits; and receiving aortic pressure information from the selectedaortic pressure interface unit.

In one embodiment, the method includes matching identified interfaceunits with a set of stored interface unit identities, and presenting, onthe touch screen, the interface unit(s) having a positive match. In oneembodiment, the method includes selecting one of the presented interfaceunits in response of a user input on the touch screen. In one embodimentthe method includes selecting one of the presented interface unitsautomatically according to predetermined selecting rules. In oneembodiment, the method the predetermined selecting rules includesparameters related to the received wireless signal. In one embodimentthe method includes receiving calibration data related to the selectedaortic pressure interface unit.

In one embodiment, the invention relates to a patient data collectionsystem for monitoring, analysing, and displaying physiologicalconditions. The system includes a pressure wire receiver unit configuredto receive a wireless signal representing a measured physiological, orother, variable in the living body; an aortic blood pressure receiverunit configured to receive, from at least one aortic pressure interfaceunit, a wireless signal including interface identity informationrequired to identify the interface unit, and information representingmeasured aortic blood pressure; a signal processing means configured tocalculate blood pressure related parameters; a touch screen configuredto display information regarding selectable aortic pressure interfaceunits and blood pressure related parameters, and to receive user input;an identifying unit configured to identify interface units based uponreceived interface identity information; a presentation unit configuredto present, on the touch screen, the interface unit(s) identified by theidentifying unit; and a selecting unit configured to select one of thepresented interface units, and wherein the aortic blood pressurereceiver unit is configured to receive aortic pressure information fromthe selected aortic pressure interface unit. The system further includesa matching unit that is configured to match identified interface unitswith a set of stored interface unit identities, and wherein thepresentation unit is configured to present, on the touch screen, theinterface unit(s) having a positive match. The selection by theselecting unit can be made in response of a user input on the touchscreen. The selection by the selecting unit can be made automaticallyaccording to predetermined selecting rules. The predetermined selectingrules include parameters related to the received wireless signal. Theaortic blood pressure receiver unit can be configured to receivecalibration data related to the selected aortic pressure interface unit.The pressure wire receiver unit and/or the aortic blood pressurereceiver unit can be detachable. The pressure wire receiver unit isconnectable to the device via a USB connection. The aortic bloodpressure receiver unit is connectable to the device via a USBconnection.

In one embodiment, the invention relates to a system for monitoring,analysing, and displaying physiological conditions related to bloodpressure within a living body. The system includes at least one aorticpressure interface unit configured to receive information representingmeasured aortic blood pressure, and to transmit a wireless signalincluding interface identity information required to identify theinterface unit, and information representing the measured aortic bloodpressure.

In one embodiment, the invention relates to a method of setting up aprobe, which can include a pressure or imaging probe, for monitoring,analysing, and displaying physiological conditions. The method includesreceiving, from at least one aortic pressure interface unit, a wirelesssignal including interface identity information required to identify theinterface unit; displaying on a touch screen information regardingselectable aortic pressure interface units; identifying interface unitsbased upon received interface identity information; presenting theidentified interface unit(s) on the touch screen; selecting one of thepresented interface units; receiving aortic pressure information fromthe selected aortic pressure interface unit. The method can furtherinclude matching identified interface units with a set of storedinterface unit identities, and presenting, on the touch screen, theinterface unit(s) having a positive match. The method can furtherinclude selecting one of the presented interface units in response of auser input on the touch screen. The method can further include selectingone of the presented interface units automatically according topredetermined selecting rules. The method can further includepredetermined selecting rules includes parameters related to thereceived wireless signal. The method can further include receivingcalibration data related to the selected aortic pressure interface unit.

This Summary is provided merely to introduce certain concepts and not toidentify any key or essential features of the claimed subject matter.

BRIEF DESCRIPTION OF DRAWINGS

The figures are not necessarily to scale, emphasis instead generallybeing placed upon illustrative principles. The figures are to beconsidered illustrative in all aspects and are not intended to limit theinvention, the scope of which is defined only by the claims.

FIG. 1A depicts a block diagram of an embodiment of a multimodal datacollection system in accordance with an illustrative embodiment of theinvention.

FIG. 1B depicts a more detailed block diagram of an embodiment of amultimodal data collection system in accordance with an illustrativeembodiment of the invention.

FIG. 1C depicts an alternate embodiment of a multimodal data collectionsystem in accordance with an illustrative embodiment of the invention.

FIG. 2A depicts an interferometer that incorporates a long sample armand long reference arm together with a reflective variable path lengthmirror and other components in accordance with an illustrativeembodiment of the invention.

FIG. 2B depicts an interferometer that incorporates an input port for aMach-Zehnder interferometer in the reference arm of a Michelsoninterferometer and other components in accordance with an illustrativeembodiment of the invention.

FIG. 2C depicts an interferometer that incorporates a variable pathlength air gap and other components in accordance with an illustrativeembodiment of the invention.

FIG. 3 depicts an opto-electronic subsystem configured to generate oneor more signals of interest in accordance with an illustrativeembodiment of the invention.

FIG. 4 depicts a block diagram of an embodiment of a digital clock inaccordance with an illustrative embodiment of the invention.

FIG. 5 depicts a block diagram of an alternative embodiment of clockgenerator in accordance with an illustrative embodiment of theinvention.

FIG. 6 depicts a schematic diagram and timing signals for an embodimentof a multi-channel data acquisition device used in accordance with anillustrative embodiment of the invention.

FIG. 7A depicts an embodiment of exemplary reference optics of a patientinterface unit (PIU) dock in accordance with an illustrative embodimentof the invention.

FIG. 7B depicts a relationship of multiple signals associated with thereference optics shown in FIG. 7A in accordance with an illustrativeembodiment of the invention.

FIGS. 8A-8C depict cross-sections of embodiments of cables used toconnect a PIU dock to an imaging engine and data acquisition computer inaccordance with an illustrative embodiment of the invention.

FIG. 9 depicts a block diagram of an embodiment of a multimodal datacollection system configured to support multiple procedure rooms inaccordance with an illustrative embodiment of the invention.

FIG. 10A depicts an ultrasound image of a fixed human coronary arteryobtained using an embodiment of the invention.

FIG. 10B depicts an ultrasound image of an OCT image of a living humanfinger pad using an embodiment of the invention.

FIGS. 11A-11C depict various exemplary non-limiting topologies by whicha principal OCT, IVUS, FFR or multimodal component is in communicationwith a one or more secondary OCT, IVUS, FFR or multimodal components.

FIG. 12 is a schematic diagram of a system showing a wireless mouse orcontroller and a mobile terminal in accordance with an illustrativeembodiment of the invention.

FIG. 13 is a schematic diagram showing a longitudinal view of a probe inaccordance with an illustrative embodiment of the invention.

FIG. 14 is a schematic diagram of a patient with respect to whichwireless measurements of FFR, image data, or other data can be obtainedusing systems and devices in accordance with an illustrative embodimentof the invention.

FIG. 15 is a schematic diagram of a probe and data collection systemcomponents accordance with an illustrative embodiment of the invention.

FIG. 16 is a schematic diagram of a data collection system and a graphicuser interface in accordance with an illustrative embodiment of theinvention.

FIG. 17 is a schematic diagram of an input device or controller inaccordance with an illustrative embodiment of the invention.

DETAILED DESCRIPTION

As described above, there are limitations to currently knownintravascular diagnostic systems. In part, the invention relates tovarious systems and components thereof for use in a catheter lab orother facility to collect data from a patient and help improve upon oneor more of these limitations. The data collected is typically related tothe patient's cardiovascular or peripheral vascular system and caninclude image data, pressure and other types of data as describedherein. In addition, in one embodiment image data is collected usingoptical coherence tomography (OCT) probes and other related OCTcomponents. OCT is an imaging modality that uses interferometry todetermine distances and other related measurements. As such, one or moreembodiments of the invention relate to interferometer designs that areconfigured for longer sample and/or reference arms while maintainingimage data levels within desirable quality levels or otherwisecompensating for certain unwanted noise or other environmental effects.

In addition, some embodiments of the invention are suitable for handlingmultiple imaging modalities. Thus, in part, the invention relates to amultimodal diagnostic system and components thereof incorporating one ormore of the following data collection modalities into a single system orapparatus OCT, IVUS, FFR, and angiography. OCT system improvements aredescribed that enable location of the patient interface unit (PIU) andimaging probe remotely from the imaging engine and/or server. This canbe accomplished over distances of between about 5 to about 100 meters(and greater in some embodiments). Using one or more interferometerswith a longer reference sample and/or reference arm can facilitate thisseparation of the imaging probe from one or more OCT system components.The inclusion of switches such as optical switches or electronicswitches to route control and/or image data signals can also beadvantageous as described herein.

IVUS imaging capabilities can also be incorporated into a systemembodiment using the same or an additional PIU. FFR pressuremeasurements can also be performed using FFR probes. For example, FFRprobes having wireless transmitters can be used. Specifically, such anFFR probe can send FFR data to one or more wireless receivers which canin turn transmit FFR data to the server. Comparison and co-registrationof OCT and/or IVUS images with angiographic images can be achieved usingdifferent configurations. For example, the data collection system (OCT,IVUS, FFR, etc.) can be configured to interface with an angiographydevice (or vice versa). Alternatively, the data collection system can beconfigured to interface with a hospital data network wherein theangiographic data is stored. In one embodiment, the PIU includes variouselements such as an electro-optic rotary coupler, rotational motor,linear travel stage, ultrasound controller, and motion controller.

To reduce clutter in the procedure room where a pullback is performed,in one embodiment, a single system or apparatus is used to dock the PIUas well as to route optical and electrical signals between the PIU,control panel, imaging engine, and data acquisition apparatus. Thissystem apparatus is a PIU dock in one embodiment. The PIU connects tothe PIU dock by mechanical fit. Docking may be assisted through the useof magnets or interlocking mechanical features on the PIU and PIU dock.An electrical connector and an optical connector are also used to placethe PIU in electrical and/or optical communication with the PIU dock. Toreduce capital costs, a single imaging engine and data acquisitionsystem capable of supporting diagnostic equipment in multiple procedurerooms can also be used.

Referring to FIG. 1A, one embodiment of a multimodal diagnostic systemor data collection system 10 may include: an imaging engine 145; aserver or computer 135 (referred to hereafter as a server) containing adata acquisition device such as a digitizer; a PIU dock 120; a PIU 115;input/output devices such as monitors 165 a and 165 b, a keyboard 170and a mouse 175. To permit near-simultaneous control by more than oneoperator, more than one keyboard or mouse can be employed. The imagingengine may include one or more of a tunable laser, fiber-opticinterferometers, polarization controllers, opto-electrical converters,electro-optical converters, optical switches, electrical receivers andsignal conditioners, and/or control systems for controlling thesecomponents. The PIU is in optical communication with a data collectionprobe along an optical path 176 that can be defined by an optical fiberin one embodiment. When configured as an integrated system, the imagingengine 145 and server 135 may be located in a separate control room. ThePIU dock 120, PIU 115, and input/output or control devices 165 a and 165b, 170 and 175, respectively, may be located remotely in a procedureroom, adjacent to a patient examination table or another common patientreference such as a support 177. A support can include a bed, anoperating table, or other apparatuses suitable for positioning a patientduring a data collection procedure. In one embodiment, the PIU dock 120includes a housing configured to receive and/or store the PIU 115 whenthe PIU 115 is not being used with a probe as part of a data collectionprocedure. In FIG. 1A major optical connections are shown as solidlines, while electrical connections are shown as dashed lines. In oneembodiment, an electrical connection can include a wireless or wiredconnection. The keyboard 170 and mouse 175 can be used as part of amobile terminal that can move between rooms as described below.

As shown in FIG. 1A, the system 10 has various features relating to theability to position the various components relative to the patientduring a procedure. Given that the patient is disposed on a support 176during a data collection procedure, the support 177 can serve as a frameof reference. The PIU 115 is in optical communication with the datacollection probe inserted in the patient and thus is in the vicinity ofor proximal to the patient and thus the support 176. The probe is usedto collect data with respect to a portion of a vessel of the patient inone embodiment. In addition, the probe includes an optical fiber thatterminates in the patient and thus, in one embodiment, is the terminusof the sample arm. The PIU Dock 120 can also be in the vicinity of orproximal to the patient or the support such that a procedure, such as adata collection session by which a blood vessel of the patient isimaged, can be performed.

A display, which can be one of the monitors 165 a, 165 b, or otherdisplay, can also be in the vicinity of or proximal to the patient orsupport 177. The display can be configured to display the imagegenerated in response to the interference data collected with the probe.In one embodiment, the PIU dock can be remote from the patient orsupport 177 such that the clinician or other system user has access tothe PIU in the vicinity of the patient. The PIU can be attached to thesupport 177 in one embodiment. The server 135, imaging engine 145, oneor both monitors 165 a, 165 b, and the keyboard 170 and mouse 175 canalso be remote from the patient or support 177. The data collected withrespect to the patient can include OCT data, IVUS data, pressure data,and other data relevant to the patient's health and/or thecharacteristics of the blood vessel being imaged. Unlike an IVUS onlysystem, which is not an optical imaging modality, allowing remoteoptical elements alone and in combination with IVUS imaging modalitiesand pressure measuring devices to operate remotely from the support 177requires various optical components and systems designed for thispurpose. Given the complexities of interferometry, optical signaltransmission and noise reduction, various embodiments of the inventionrelate to addressing the challenges of remotely locating or allowingflexibility of moving some of the optical components of a datacollection system between rooms or between different locations. Inaddition, the challenge of integrating different signals, such asacoustic, electrical, and optical signals are also addressed withdifferent embodiments as described herein.

The system 10 can be used with a patient as shown with the variouselements of the system being located in the vicinity of the patient orproximal to the patient. Alternatively, certain components of the system10 can be positioned remotely from the patient such as in other parts ofthe same procedure room the patient is in, but not near the patient foruse by an operator or clinician or in a different room relative to thepatient. This can be facilitated by the patient being disposed in asupport 177 during a probe-based data collection procedure. An opticalfiber portion connects the PIU 115 to the patient as shown. The PIU dock120 and the PIU 115 are typically near a patient such as connected to orpositioned near the support 177.

Referring also to FIG. 1B, the system 12, in more detail, includes inone embodiment, an imaging engine 145 that includes a light source 147,a Mach-Zehnder Interferometer (MZI) 149, and a Michelson interferometer151 or one or more other OCT system components. The system 12 of FIG. 1Bis configured to allow the same remote and proximal positioning ofdifferent system components as otherwise described herein with differentembodiments. As shown, two signal lines are in communication with theMZI 149 from the digitizer 134 of the server 135. One of these signallines is a line trigger, such as for example the line connected to theBragg grating 370 of FIG. 3 and, the other signal line is the k clock,which can be the k clock signal in FIG. 3. The line trigger and the kclock can be sent to the MZI from the digitizer 134. The light source147 may be any device that produces a swept wavelength output as afunction of time. The light source can be selected for use infrequency-domain, swept-source, or Fourier-domain OCT (genericallyFD-OCT). The system 12 may also be configured as a spectral domain(SD-OCT) or time domain (TD-OCT) OCT system by incorporating a suitablelight source 147 such as a broadband light source and spectrometer, inthe case of SD-OCT.

In one embodiment, the imaging engine 145 can also include a referencearm (RA) optical switch 153, a sample arm (SA) switch 155, and anultrasound (US) switch 159 in communication with an opto-electrical(O/E) converter 157. As used herein, US refers to ultrasound such as anIVUS or other ultrasound-based data collection modality. In oneembodiment, US can also include pressure transducer data such as datasuitable for FFR measurements. However, in one embodiment the imagingengine may only include a digitizer and/or a light source such as alaser. The switches can be controlled by control lines in the imagingengine 145. Electrical signals from the MZI 149, the Michelsoninterferometer 151 and the O/E converter 157, are sent to a digitizer134 within the server 135. The positions of the ultrasound switch 159and O/E converter 157 may also be reversed, such that the US switch 159is an electrical switch instead of an optical switch and the O/Econverter 157 is a multi-channel O/E converter.

Control signals from the server 135 are sent to the PIU dock 120 by wayof an optical link 136. Input/output devices such as a keyboard 170,mouse 175 and monitor 165 a provide an interface to the server 135 foran operator. The server 135 in various embodiments is connected to ahospital network through a network hub 143 and receives angiography datafrom an angiography system 144 through the network hub 143. A videoswitch 140 provides video information to one or more video monitors 141in various locations as applicable.

The PIU dock 120 is connected by optical cable 137 to the RA switch 153.Light is communicated to and from the RA switch 153 from and to,respectively, the reference optics 121 of the PIU dock 120. Theconverted optical signals are sent to and used by the ultrasoundelectronics 150 of the PIU 115. Similarly, light is communicated to andfrom the SA switch 155 by an optical cable 138 from and to,respectively, a rotary coupler 152 of the PIU 115. The PIU 115 is inoptical communication with a length of optical fiber that is part of thesample arm as shown. This length of fiber is connected to a datacollection probe disposed in a subject such as a patient prior tocollecting image data or other data. Finally optical signals pass to theUS switch 159 of the imagining engine 145 over an optical cable 139 froman electrical to optical (E/O) converter 122 of the PIU dock 120. In oneembodiment, electrical signals from the ultrasound electronics 150 ofthe PIU 115 are sent to the E/O converter 122.

Signals from the server 135 communicated to the PIU dock 120 over theoptical cable 136 enter the hub 123. Electro-optical conversion takesplace in the server 135, while opto-electrical conversion takes place ina converter in the hub 123. Other conversion devices and configurationsrelating to when and what devices perform conversion can be used. Thehub 123 sends and receives instructions to and from a control panel 133and to and from a PIU communications port 127 which is used to controlmotion of the motors of the PIU 115. The motors of the PIU can be usedto rotate and pullback an OCT and/or ultrasound imaging probe interfacedtherewith or other functions. The hub 123 also provides control signalsand receives measurement data to and from the FFR-AO 129 and FFR-PW 130receivers as described below. AO refers to aortic pressure and PW refersto pressure wire in one embodiment. The pressure data receivers 129, 130can be used to receive pressure data from one or more pressuretransducers and can be used for FFR measurements and other purposes. Inone embodiment, pressure data is wirelessly transmitted to the pressuredata receivers.

FIG. 1C shows an alternative embodiment of a system 15 that includesseveral of the components of FIG. 1B. As an alternative to generatingthe ultrasound trigger pulse or signal directly in the PIU dock 120, thetrigger information can instead be transmitted from the imaging engineto the PIU dock along the same optical fiber used to carry theultrasound image information. The electronic trigger signal can becreated by a controller 158 such as microcontroller in the imagingengine 145 and can then be converted to an optical trigger signal withan E/O converter 157 b, where the E/O converter wavelength is selectedto be different than the wavelength used to carry ultrasound data. Theoptical trigger signal may then be combined onto the fiber carryingultrasound image data by use of a wavelength division multiplexing (WDM)filter 160 a.

In turn, the trigger signal may then be transmitted to the PIU dock 120,separated from the ultrasound image data by another WDM filter 160 b,and converted back into an electrical signal by an O/E converter 122 b.This trigger signal may then be passed to the US electronics and triggergeneration of an ultrasound pulse. The timing of the electronic triggermay be adjusted by a microcontroller such that ultrasound image data andOCT image data arrive back at the digitizer board 134 in the server 135at the same time. There are certain advantages associated with using afirst WDM filter and a second WDM filter with a reflector or mirror 163.This arrangement has the advantage of reducing the number of opticalcomponents required in the PIU dock 120, since only a fixed mirror 163is required to be in communication with the reference arm instead of afixed mirror, splitter, circulator, and fiber Bragg grating.

The microcontroller 158 can be configured to generate an electricaltrigger pulse that is converted to an optical pulse in the O/E converter157 a. The first WDM 160 a is used to merge the trigger pulse onto thesame optical fiber carrying the ultrasound image data (which is flowingin the opposite direction). The second WDM 160 b in the PIU dock is usedto split the optical trigger pulse apart from the optically transmittedultrasound image data. The optical trigger pulse is converted back to anelectrical trigger pulse in the O/E converter 122 b, and is then sent tothe US electronics in the PIU 115 where it triggers generation of anoutgoing ultrasound pulse. In one embodiment, converter 122 a is usedfor the transmission of ultrasound image data from the PIU 115 to theserver 135. Converter 122 a is linked to converter 157 a. Themicrocontroller is configured to synchronize the transmission of theelectrical trigger pulse such that an outgoing ultrasound pulse iscreated in the PIU at the same time that the first wavelength in an OCTsweep is passing through the PIU 115 on its way to the catheter-basedOCT image data collection probe. The microcontroller 158 is linked tothe server 135 to allow for updating the microcontroller firmware andchanging the delay time settings. In one embodiment, as shown in FIG.1C, the microcontroller 158 is configured to generate a trigger pulsethat it would not otherwise generate if the first and second WDMs 160 a,160 b were not incorporated in the embodiment. In addition, in oneembodiment, FIGS. 1B and 1C depict various components which include oneor more networks that includes links between various primary andsecondary components. These links can be optical, or electrical invarious embodiments. Electrical links or in electrical communicationincludes wireless communication or links in one embodiment.

In one embodiment of the imaging engine 145, the interferometer 151 is aMichelson interferometer as shown in detail in FIG. 2A. A portion oflight from the light source 147 arrives at a first optical coupler 308such as for example a 90/10 optical coupler. A fraction of light fromone output of the coupler 308 is directed towards a sample arm (SA) 309,while another fraction is directed towards a reference arm (RA) 311. Thecoupling ratio of the first optical coupler 308 is preferably selectedto direct a majority of the light to the sample arm 309 in order toobtain high sensitivity OCT images. In one embodiment, the couplerdirects 90% of the light towards the sample arm 309 and 10% of the lighttowards the reference arm 311.

The reference arm 311 includes a 4-port circulator 317, arranged suchthat light entering port 1 from the coupler 308 is directed to areflective variable path length mirror (VPLM) 319 in communication withport 2 of the circulator 317. In one embodiment, the VPLM 319 iscontrolled by a controller 158. The VPLM 319 can be any reflectivedevice where the light travels through an adjustable optical path tomatch the path length in the sample arm 309. In one embodiment, the VPLM319 is formed with a collimating lens, an air gap, and a translatablemirror. Preferably, the VPLM 319 employs retro-reflecting optics, suchas an optical corner cube reflector, to reduce sensitivity tomisalignment and drift.

Light returned from the VPLM 319 is directed to port 3 of the circulator317 which is in optical communication with a 1×N optical RA switch 153(not shown). Here, N is the maximum number of procedure rooms that canbe supported by the imaging engine. N can be any number supported byoptical switch technology, but is preferably between 2 and 8. Lighttravels through the reference arm 311 through the RA switch output tothe PIU dock (FIG. 1B) 120, which may be located a distance away (about5 to about 100 meters) in a remote procedure room. In contrast to thepresent invention, previously-known interferometer designs have confinedthe entirety of the reference arm to the imaging engine. While this isacceptable for short (less than about 5 meters) distances between theimaging engine and the sample to be imaged, limitations arise when thedistance between the imaging engine and the sample to be imaged are long(greater than about 5 meters).

In turn, environmental fluctuations between the imaging engine and theportion of the sample arm not contained in the imaging engine lead torelative changes in optical path length, stress, chromatic dispersion,birefringence, and polarization mode dispersion between the referencearm and sample arm, which results in degradation of image quality andnecessitates complex correction software or hardware to be applied. Inone embodiment, the majority of the optical paths of the reference andsample arms are exposed to the same environmental conditions,eliminating this problem. The ability to accommodate long opticalinterconnections between the optical engine and the PIU dock permitsflexible placement of the bulky hardware at locations remote from thepatient table where the procedure is performed. A portion of thereference light returns from the PIU dock 120 and passes back throughthe RA switch 153 and is directed to a polarization controller (PC) 323through port 4 of the circulator 317. The PC 323 is adjusted to matchthe polarization state of the reference light to the state of the samplelight, thereby maximizing the intensity of the resulting interferencepattern generated at the 50/50 coupler 327.

The sample arm SA 309 also includes a 4-port circulator, arranged suchthat light entering from the coupler 308 in port 1 is first directed toa reflective mirror 312 connected to the port 2. The mirror 312, invarious embodiments, is a Faraday mirror, a fiber coated with areflective material, a bulk mirror, or any other reflective structure.Since light in the RA 311 makes three total passes through thecirculator material 317, a matching 4-port circulator 310 is used in theSA 309 as well. Light travels from port 3 of the SA circulator 310 andenters a 1×N optical switch 155 (not shown). Light travels from the SAswitch 155 output to the PIU dock (FIG. 1B) 120, where it passes throughto the PIU 115 and is directed to an imaging catheter via a rotaryoptical coupler. Instead of a 4-port circulator 310 a 3-port circulatorcan be used in the SA 309 to reduce transmission losses; however, itwould then be necessary to match the total chromatic and polarizationmode dispersion of both arms of the interferometer to avoid broadeningof the OCT point spread function. Alternatively, a transmissive opticaldelay line and a pair of 3-port circulators can be used instead of theVPLM and the pair of 4-port circulators 310 and 317.

Light returning from a coronary blood vessel, or other tissue sample, ascollected by a forward scanning or side scanning rotatable optical fiberin an OCT probe, passes back through the SA switch 155 and is directedfrom the fourth port of the SA circulator 310 to the 50/50 coupler 327.The sample and reference light beams combine within coupler 327. Theinterference pattern is converted to an electrical signal by a balanceddetector 328 and is transmitted to a first channel of a digitizer 134 inelectrical communication with the server 135.

Another embodiment of the invention relating to an interferometer asshown in FIG. 2B. In this embodiment, a Michelson interferometer iscombined with a MZI. As an alternative method for achieving lengthmatching between the MZI path and the Michelson path, light returningfrom the remote procedure room in the reference arm of the Michelsoninterferometer is used as the input to the MZI.

FIG. 2B includes various optical elements that are also used in FIGS. 2Aand 3. As shown in FIG. 2B, an optical coupler 308 may be connected tothe fourth port of the optical circulator in the reference arm, forexample, and may direct 10% of the reference arm light to the input ofthe MZI. A second coupler 308 having the same split ratio may optionallybe connected to the fourth port of the optical circulator in the samplearm in order to match the spectral transmission characteristics of thereference arm. This configuration is advantageous since anotherpath-matching fiber of length 2L is not required to equalize the time offlight of light in the MZI to that of light in the Michelsoninterferometer, reducing the size of the overall optical assembly.Additionally, since light travels in a common mode configuration throughthe reference arm and the MZI until such light reaches the splitter atthe MZI input, variations in dispersion between the two interferometersare minimized and the OCT point spread function is not substantiallydistorted. As shown, loop R corresponds to a small path delay 383 thatis used to generate a reference interference fringe where thezero-crossings are uniformly spaced in optical frequency.

Yet another interferometer embodiment is shown in FIG. 2C. FIG. 2Cincludes various optical elements that are also used in FIGS. 2A, 2B and3. In this embodiment, a Michelson interferometer is used with atransmissive reference path. The Michelson interferometer can also beconfigured to incorporate two three-port circulators instead of twofour-port circulators. Two three-port circulators 313, 317 are used inone embodiment. In FIG. 2C, three-port circulator are used such that themirror shown in embodiment of FIG. 2A is removed.

In this configuration, the variable path length mirror is replaced witha variable path length air gap (VPLAG) 167 that transmits light ratherthan reflects light. A microcontroller 158 is in electricalcommunication with the VPLAG 167. Thus, the path length of the VPLAG 167changes over time in response to input control signals from themicrocontroller 158. In one embodiment, the VPLAG 167 includes twocollimating lenses and air gap wherein one lens is mounted on a motorsuch that when the motor is actuated the air gap changes. The VPLAG 167can be controlled by the microcontroller 158. This configuration isadvantageous since three-port circulators are less expensive and sufferfrom lower insertion losses than four-port circulators, althoughtransmissive air gaps are more prone to misalignment and drift thanreflective systems. The VPLAG 167 can be located in the remote procedureroom, such as in the PIU dock or PIU. It is also understood that areflective VPLM could be located in the PIU dock or PIU.

Exemplary details of the MZI 149 and auxiliary electro-optical circuitsof an imaging engine embodiment 145 are shown in FIG. 3. FIG. 3 depictsan opto-electronic subsystem 350 suitable for generating one or moresignals of interest such as a k-clock, sweep trigger, and intensitymonitor. A portion of light from the light source 147 arrives at anoptical coupler 358 and is split by the optical coupler 358 into twofractions. One fraction of light from the coupler 358 is directedtowards the MZI 149, while another fraction is directed towards anotheroptical coupler 363. The coupling ratio of the first optical coupler 358is preferably selected to direct equal amounts of light to the MZI 149and the second optical coupler 363. Light entering the second opticalcoupler 363 is in turn split into two other portions. One portion isdirected through a 3-port circulator 368 to a fiber Bragg grating (FBG)370 and the other portion is directed to photodetector 375.

The FBG 370 reflects only a narrow bandwidth of the incident light at aknown wavelength, such that an electronic pulse is generated by thephotodetector 372 each time the light source 147 sweeps through theknown wavelength. A time-delayed version of this pulse is transmitted tothe digitizer 134 and is used to trigger acquisition of individual imageline data from an OCT probe positioned using a catheter and coupled to aPIU. A second portion of light output from the second optical coupler363 is directed to a photodetector 375 that produces a time-resolvedintensity trace of the light source emission. This signal is returned toa local controller 378 inside the imaging engine 145 for controllingparameters such as the light source intensity.

The second fraction of light exiting the first optical coupler 358enters a fiber-optic delay line 379 having length 2L, where L is equalto the length of the cables 136, 137, 138, 139 connecting the imagingengine 145 and server 135 to the PIU dock 120. The path length of thedelay line 379 must be matched to the connecting cables 136, 137, 138,139 in order to ensure synchronization between the clock signalgenerated from the interference pattern generated by the MZI 149 and theinterference pattern generated in the Michelson interferometer 151. Inembodiments of this invention where the PIU dock 120 is located remotelyfrom the imaging engine 145, L is the main contributor to the overalloptical path length of the system. Still, it is understood that thecomplete path lengths of the Michelson interferometer 151 and MZI 149must be matched from the point where light is directed out of the lightsource 147 to the point where the resulting electronic signals arereceived by the digitizer board 134. In one embodiment, the path lengthsare also matched for electrical signals. L should be at least 5 meterslong to allow a cable to be run from a control room to a procedure room.Preferably L should be at least 30 meters long to allow connection ofmultiple procedure rooms to a main control room. In some settings Lshould be at least 100 meters long if the procedure rooms are separatedby long distances or are located on different floors of a building.

After passing through the 2L delay line, the light enters the firstcoupler 380 of a standard MZI 149 with a path imbalance R 383. The MZIinterference pattern in the second coupler 387 is converted to anelectronic signal by a balanced detector 390, and a series of pulses atevenly spaced optical frequency intervals is generated by a clockgenerator 392 to form the k-clock pulses. Here, “k” refers to thecommonly-used symbol for optical frequency. Path imbalance R 383 isselected such that the MZI 149 generates interference fringes at afrequency corresponding to the desired OCT system imaging depth, takinginto account any electronic clock rate modifications in the clockgenerator circuit and correcting for the refractive index of the opticalfiber. For example, if the desired OCT imaging range is about 10 mm inair and one k-clock pulse is generated during each MZI interferencefringe cycle, then R should be (4×10 mm)/1.4676 or about 27.3 mm. If,for example, the k-clock frequency is quadrupled electronically in theclock generator circuit, then R should be about 6.8 mm.

After the k-clock signal is generated, the overall time delay andindividual spacing of the k-clock pulses can be adjusted in the clockdelay circuit 394. The purpose of this circuit is to compensate forresidual path length mismatches between the MZI 149 and Michelsoninterferometer 151, and to compensate for dispersion imbalances betweenthe reference arm and sample arm of the Michelson interferometer 151.Although the optical fibers in the reference arm and sample arm areconfigured to minimize these imbalances, slight differences in the coresizes and the stresses applied to the fibers give rise to chromaticdispersion and polarization dispersion, which can degrade the resolutionof OCT images.

To reduce dispersion-induced image degradation, the spacing between theedges of the pulses generated by k clock during the laser sweep intervalcan be altered. Thus, in one embodiment the interval is adjustedslightly such that the OCT interference signal is sampled at the propertimes to compensate for residual wavelength-dependent optical groupdelay.

FIG. 4 depicts an embodiment of a digital clock generator that allowsadjustment of the intervals between k-clock pulse edges according to apreset or feedback controlled profile. In one embodiment, the clockgenerator 392 enables dynamic adjustment of the intervals betweenk-clock edges according to a sequence of control words stored in alook-up table. Each value of the look-up table is a digital word thatsets the interval by which a given pulse edge is delayed relative to thepreceding pulse edge. This embodiment of the clock generator includes aprogrammable electronic delay line 394 in which the binary control wordthat sets the delay interval is loaded from a look-up table 715. In oneembodiment, light from light source resets the counter. In oneembodiment, the k clock sets the clocking for the counter.

To set each delay interval between the output clock edges on which theOCT signal is sampled by the analog-to-digital converter (ADC), a newcontrol word is loaded on the leading edge of each input clock pulse.Between successive falling edges of the delayed pulse train, there is atime interval. This time interval increases or decreases according tothe sequence of control words stored in the look-up table. In thismanner, a delay curve of an arbitrary shape can be superimposed on thek-clock. Typically, compensation of small amounts of residual dispersioncan be accomplished with a polynomial curve described by a fewcoefficients. If only a linear delay profile is required, the look-uptable 715 can be replaced with a simple binary counter 720.

FIG. 5 shows an alternative configuration of a digital clock generator392 based on a subsystem 760 that includes a monostable multivibratorwith voltage-modulated pulse width. This subsystem 760 employs avoltage-adjustable pulse width or arbitrary waveform generator 763 toset the intervals between the k-clock edges. The generator 392 is inelectrical communication with a monostable multivibrator 760. Thegenerator can be a function generator or other suitable waveformselectable generator. This clock generator embodiment enables dynamicadjustment of the intervals between k-clock edges according to the shapeof an applied waveform. In this embodiment, the output of the k-clockgenerator 392 is an input to a monostable multivibrator 765 that can beimplemented using a flip-flop component with the D input held at 1. Theoutput of a comparator 770 resets the flip-flop of the monostablemultivibrator 765. The inverting input of the comparator 770 isconnected to the output of an arbitrary waveform generator 763 which istriggered by a laser scan pulse 753. The laser scan pulse, derived fromthe FBG synchronization signal 372 in FIG. 3, for example, initiates thegeneration of the arbitrary waveform at the beginning of each laserscan.

If a threshold voltage V2 is applied to the inverting terminal ofcomparator 770 and is held constant, the width of the pulse produced bythe monostable multivibrator 765 is determined by the time required tocharge capacitor C through resistor R. However, when V2 from the outputof the arbitrary waveform generator 763 varies in time, the pulse widthvaries dynamically in synchrony with the laser sweep. The OCT imageresolution is optimized by adjusting the coefficients of a polynomialfunction that defines the waveform such that the width of thepoint-spread function of the OCT system is minimized. This adjustmentcan be accomplished manually by trial and error or by computer accordingto a programmed optimization routine.

An exemplary embodiment of the multi-channel digitizer or device 134that samples the OCT and ultrasound signals in the server 135 is shownin FIG. 6. In one embodiment, the 134 is configured for simultaneous,asynchronous sampling of optical coherence tomography and ultrasoundsignals. At least one channel of the digitizer 134 is dedicated to OCTsignal acquisition. In one embodiment, at least one other channel isdedicated to ultrasound signal acquisition. It is understood thatadditional channels can be used for specialized types of OCT imaging,such as polarization-sensitive OCT. The sweep trigger generated by thephotodiode 372 in communication with the FBG 370 in the MZI 149 occursat a fixed wavelength position during each scan. By applying a fixeddelay time to the sweep trigger, the pulse can be shifted to occur atthe starting point of each OCT and US image line and can therefore beused as a line trigger that initiates acquisition of each OCT and USimage line.

Because the number of image lines generated per second may be differentfor the OCT and ultrasound components of a multimodal image datacollection system, the digitizer 134 may be configured to downsample thesweep trigger on one acquisition channel. For example, the OCTcomponents may generate 200,000 image lines per second whereas theultrasound components may generate 100,000 images line per second. Sincethe sweep trigger is also generated at a rate of 200,000 pulses persecond, the digitizer 134 may be configured to ignore every second sweeptrigger pulse for acquisition on the ultrasound channel.

In addition to the sweep trigger, the digitizer 134 also receives thedigital k-clock pulse train that triggers acquisition of each sample ofthe OCT interference signals. In FIG. 6, the k-clock signal S2 or 601 isshown as a group of unevenly spaced pulses. Pulses corresponding to oneOCT sweep are shown as clear boxes, and pulses corresponding to thesubsequent OCT sweep are shown as hatched boxes. Although only a smallnumber of k-clock pulses is shown, it is understood that up to severalthousand samples may be acquired during each OCT sweep. The ultrasoundsignals S4 or 602 are acquired using a fixed-frequency sample clockgenerated internally by a crystal oscillator 625 located on the dataacquisition card. In FIG. 6, for illustrative purposes only, theultrasound line rate S4 is shown as being 50% of the OCT line rate 603or S3.

In the embodiment shown the digitizer 134 may be configured to performfast Fourier transforms (FFT) on the OCT channel and/or the ultrasoundchannel using a field programmable gate array (FPGA), digital signalprocessing (DSP) chip, application-specific integrated circuit (ASIC),or other digital logic device 615, 623. In FD-OCT systems, it isnecessary to perform an FFT prior to forming tomographic images. An FFTstep is not required to form conventional ultrasound images, although anFFT may be applied to conduct frequency analysis of the ultrasound data.

Additional signal processing steps such as logarithmic scale compressionand digital filtering may also be incorporated onto the data acquisitiondevice, such as for example, a digitizer as described herein, to reducethe burden on the server. After data acquisition and FFT processing, theOCT and US image lines are buffered, re-synchronized, and transmitted bya bus chip 617 to the computer's signal bus. The lines are stored insystem memory for further processing and conversion to OCT and IVUSimages.

In one embodiment, the imaging engine 145 can also contain componentsfor receiving and converting ultrasound data transmitted from the PIUdock 120. Because ultrasound signals of the type used for intravascularimaging typically occupy a portion of the frequency spectrum from 0 Hzto less than about 200 MHz, these signals can be converted to opticalsignals and transmitted over long distances without degradation usingmultimode or single-mode optical fiber. The optical signal is passedbetween the imaging engine 145 and the PIU dock 120 through the 1×Noptical US switch 159. The output of the switch 159 (FIG. 1B) isconnected to the optical to electrical (0/E) converter 157, whichconverts the optical signal back into an electronic form. The O/Econverter 157 can be a simple photodetector with a transimpedanceamplifier. The electrical rendition of the ultrasound signal is thendirected to a second channel of a digitizer 134 in the server 135.

The O/E converter 157 in the imaging engine and the E/O converter in thePIU dock are in optical communication with each other via an opticalfiber as shown in FIG. 1B. In one embodiment, US signals are collectedusing a US probe and transmitted using a conductor such as a wire withsuitable shielding. In other embodiments, as shown in FIG. 1B all of thedata collected using OCT or US is transmitted by a plurality of opticalfibers. Three optical fibers for the sample arm, the reference arm, andthe US optical signal are shown in FIG. 1B. Although some of the lengthsin the figures are shown as L, the lengths can be the same or differentin various embodiments.

A laser diode or other light source in the E/O converter 122 can receivean input radio frequency or other type of signal from the US probe andmodulate the light source in the E/O converter. The modulation can bedigital or analog. In a preferred embodiment, the modulation is analog.The optical signal from the converter 122 includes the US data from a USprobe. This optical signal is transmitted to the other converter 157where the optical signal is converted back to an electrical signal fortransmission to the server. This paired system of an optical toelectrical converter, an optical fiber, and an electrical-to-opticalconverter reduces the need for shielding and avoids degradation of theUS signal by electrical attenuation or dispersion in long electricaltransmission lines and electromagnetic interference from externaldevices.

The PIU dock 120 serves both as a mechanical mount for the PIU 115 whenthe PIU 115 is not in use, and as an opto-electrical interface betweenthe PIU 115, control panel 133, imaging engine 145, and server 135. ThePIU dock 120 can include reference optics 121, an electro-opticalconverter 122, a digital link hub 123, wireless pressure or FFR datareceivers 129, 130, and circuitry 127 for electronic communication withthe PIU.

Exemplary reference optics 121 of the PIU dock 120 are shown in FIG. 7A.An optical coupler 408 directs a fraction of light received from thereference arm switch 153 towards a fixed mirror 410, while anotherfraction of light is directed towards a circulator 413 such as athree-port circulator. The coupling ratio of the optical coupler 408 ispreferably selected to direct the majority of light to the fixed mirror410. The fixed mirror 410 in various embodiments is a Faraday mirror, afiber coated with a reflective material, a bulk mirror, or any otherreflective structure. This mirror 410 forms the terminal end of theMichelson interferometer reference arm 311. Placing the terminal end ofthe reference arm 311 in the PIU dock 120 ensures that the lightundergoes substantially the same environmental variations whiletraveling through the reference arm and sample arm, except for theportion of the sample arm located in the PIU 115 and imaging catheter orprobe.

To facilitate the generation of ultrasound pulses synchronously withexposure of the sample tissue to OCT light, the PIU reference optics 121includes, in one embodiment, a circulator 413, a Fiber Bragg Grating(FBG) 416, and photodetector 418 configured to send a pulse transmittrigger to the ultrasound electronics 150 in the PIU 115. The FBG 416reflects light over a narrow range of wavelengths, and is selected toreflect the same narrow range of wavelengths as the FBG 370 (FIG. 3)located in the imaging engine 145. For example, in an embodiment asshown in FIG. 7A, the FBG 416 is selected to reflect a narrow range ofwavelengths at the center of the spectrum of the OCT light. Thephotodetector (PD) 418 generates an electrical pulse at a timecorresponding to the center of the light source sweep.

In addition, as shown, a programmable delay circuit 422 is configured todelay this pulse by approximately ½ of the sweep period, such that theresulting ultrasound pulse transmit signal occurs at the beginning ofthe subsequent light source sweep. An ultrasound pulse P4 is generatedfrom a transducer when the ultrasound control electronics receive thepulse transmit signal P3. This is shown in FIG. 7B, where the pulsetransmit signal P3 from the first OCT line is shown as a clear pulse andis a time-delayed version of the corresponding PD signal P2, also shownas a clear pulse, from the first OCT line. The subsequent pulse transmitsignal P3, aligned to the second OCT line, is a time-delayed version ofthe corresponding subsequent PD signal P2, where both are shown ashatched pulses. In this way, ultrasound pulses P4 are generated by thetransducer at the tip of the US imaging probe at the same time that OCTlight illuminates the sample, thereby preventing mis-synchronization ofOCT and ultrasound image data.

The PIU dock 120 can also incorporate the digital communication hub 123(FIG. 1B), whereby a single digital link 136 to the server 135 is splitinto multiple ports. Any suitable digital link, such as Ethernet, can beused. In one embodiment, the digital link can for example be an opticalUSB link and the hub can be a USB hub. Use of a single link, multi-porthub architecture minimizes the number of cables required to connect theserver computer to the PIU dock 120.

As shown in FIG. 1B, one port of the hub is used as an interface betweenthe PIU motor drive circuitry 161 and the server 135. In one embodiment,PIU communication circuits 127 are used to reformat control commandssent from the server 135 to the PIU 115. A second port of the hub 123 isused to connect a wireless receiver 129 that receives pressure data froman aortic pressure monitor 129. A third port of the hub is used toconnect a wireless receiver 130 that receives pressure data from aninvasive pressure wire. In this way, wireless FFR measurements can bemade and transmitted to the server 135. Other pressure data-basedmeasurements and parameters can also be determined and sent to theserver.

A fourth port of the hub 123 is connected to the control panel 133. Thecontrol panel 133 may be a touch-sensitive display device; a series ofdiscrete buttons and switches; or both a touch-sensitive area and aseries of discrete buttons and switches. The control panel 133 may alsoincorporate an input or pointing device such as a track pad, mouse,joystick, roller ball, stylus, or other pointing device known in theart. The control panel 133 may be used to control operation of thecomplete diagnostic system, and may be mounted in the procedure room orbe movable as a mobile terminal. The control panel 133 may include awireless mouse and a mouse pad, in wireless communication with the PIUdock 120. Additional hub ports may be provided to allow connection ofexternal digital devices, such as portable storage devices or additionaldiagnostic devices.

The PIU 115 is configured to interface with an OCT imaging catheter orprobe, an IVUS imaging catheter or probe, and/or a catheter or probecapable of conducting both OCT and IVUS imaging. The PIU 115 contains arotary coupler 152 that transmits optical signals, electrical signals,or both. A portion of the sample arm of an interferometer is disposed inpart of the patient interface dock in one embodiment and in the patientinterface dock and patient interface unit in another embodiment. Motordrive electronics 161 receive control commands from the server 135 thathave been routed through the PIU dock 120. The motor drive electronics161 control motors that produce rotary and linear motion, therebyspinning and pulling back or advancing the imaging or data collectioncatheter/probe. The PIU 115 in one embodiment also contains ultrasoundelectronics 150. These ultrasound electronics can be an ultrasoundsystem that can be configured to perform one or more of the following:generating ultrasound pulses, receiving ultrasound signals returned fromthe sample, and switching the device between transmit mode and receivemode. Locating the ultrasound electronics 150 in the PIU 115 isadvantageous for reducing losses and dispersion between the pulsegenerator and the ultrasound transducer, and reducing electromagneticinterference effects.

In accordance with one embodiment of the invention, OCT light travelsbetween the imaging engine 145 and the PIU dock 120 over two opticalfibers 137, 138 of length L, or other lengths, with one fiber carryingreference arm light and the other fiber carrying sample arm light. Inone embodiment, the two optical fibers are single-mode fibers, such asCorning SMF-28e or an equivalent. The two fibers are arrangedside-by-side in a common cable enclosure. This arrangement is beneficialfor reducing the effects of environmental fluctuations on the OCTinterferometer. Changes in temperature induce changes in optical pathlength of optical fiber. If the path length of one arm of the Michelsoninterferometer changes relative to the other arm, the OCT images willappear to shift in the axial direction. As a result, under suchcircumstances images of a sample of interest will be distorted.Enclosing the two optical fibers in a common cable enclosure alsoreduces the differential effects of stress, chromatic dispersion,birefringence, and/or polarization mode dispersion caused byenvironmental fluctuations, which in turn reduces degradation of OCTimage quality.

By co-locating the fibers in a common cable such as a jacket orinsulating sheath, temperature fluctuations in the cable will causesubstantially the same path variation in the reference and sample armsof the Michelson interferometer. The path variations will thereforecancel one another, and the appearance of the OCT images will not bealtered. In addition, local stresses caused by bending and twisting ofthe cable will be substantially the same in both fibers. Thisarrangement reduces differential polarization rotation and polarizationmode dispersion in the two arms of the Michelson interferometer 151,which can degrade OCT image quality. Although the drawings explicitlyshow only the cable portions having a path length of L, the completepath lengths of the reference arm and sample arm in the Michelsoninterferometer 151 are matched in one embodiment to perform OCT imaging.

FIG. 8A shows a cross-section of a cable assembly that can be used toconnect the control room to a procedure room. In this embodiment, threeoptical fibers 510 used to transmit the sample arm light, reference armlight, and optically-converted ultrasound signal are placed inside of acommon cable or jacket 512. A fourth optical fiber 505, used as theoptical digital link between the server 135 and PIU dock 120, may beplaced in a separate cable or jacket 507. The optical digital link mayrequire additional optical fibers, which may also be disposed within thejacket 507.

In those situations in which system power is provided by the imagingengine 145 to the PIU dock 120 and PIU 115, two additional electricalconductors 523 may be placed within an inner jacket such as for exampleseparate braided shield 522 to supply power. The entire assembly may beenclosed in a common protective sheath such as an outer cable or jacket503 to provide environmental protection. A cross-section of analternative cable assembly is shown in FIG. 8B. This assembly can beused when system power is available in the procedure room. In this case,the cable assembly is entirely optical, no metal conductors such ascopper wire are disposed within the cable assembly, and is immune fromelectromagnetic interference and electrical hazards. In otherembodiments, conductive elements such as metal wires can be disposed inthe protective sheath to supply power or transmit electrical signals. Inone embodiment, for a given cable embodiment one or more of the opticalfibers can be used for data transmission, one or more conductors can beused for electrical power transmission, and one or more mechanicalstrength members are disposed within a common protective sheath.

Alternatively, all optical fibers and electrical conductors may bedisposed along with mechanical strength members, such as aramid yarn orKevlar fibers, within an outer jacket 503 without the use of innerjackets 512, 522, and 507. An example of such an embodiment is shown inFIG. 8C. As shown, an outer jacket 503 defines an interior cavity thatcan include various optical and electrical conductors and strengthmembers 530. Various optical fibers configured to carry OCT data 535 areshown. An optical fiber configured to transmit ultrasound data 540 canalso be disposed within outer jacket 530. One or more digitalcommunication fibers 545 can be used to carry suitable data, such ascontrol signals, or other digital information. In addition, one or moreelectrical conductors 550 can also be disposed within outer jacket 530.The various optical fibers can be single mode or multimode as applicablefor a given application.

In many interventional cardiology settings, each procedure room isadjacent to a dedicated control room. Physicians, nurses, andtechnicians work in teams split between the procedure room 204 and itsassociated control room 200. FIG. 9 shows a simplified block diagram ofthe system components configured for imaging in multiple procedure roomsusing a single imaging engine 145 and server 135. Major electricalconnections are shown as dashed lines, and major optical connections areshown as solid lines. The optical switching network (S) in the imagingengine 145 incorporates the SA switch 155, RA switch 153, and ultrasound(US) switch 159 shown in FIG. 1B. All connections between the maincontrol room 200 and the procedure rooms 204, 208 are the same as theconnections shown in FIG. 1B.

A satellite procedure room 208 may be linked to the imaging engine 145and server 135 in the main control room 200 with a cable assembly oflength L containing the same type and number of optical fibers and/orelectrical conductors found in the cable assembly linking the maincontrol room 200 to the main procedure room 204. The satellite procedureroom interfaces to the imaging engine 145 through the switching network(S), and interfaces to the server 135 through a digital optical link.Even when the diagnostic system is in use in the satellite procedureroom 208, all data acquisition and signal processing tasks are conductedin the server 135. Processed diagnostic data including OCT images, IVUSimages, FFR data, and angiographic data is passed from the server 135 toa client computer 220 in a satellite control room 230 over a datanetwork.

The client computer 220 receives processed diagnostic data from theserver 135 and directs the data to a monitor bank 141 in the satelliteprocedure room 208. The processed data may be routed through a videoswitch 140. Because certain aspects of diagnostic system operation areoften controlled by personnel in the control room instead of or inaddition to personnel in the procedure room, it is also desirable toprovide control mechanisms for the diagnostic system in each satellitecontrol room 230. To this end, the client computer 220 is provided witha keyboard, mouse, and monitor in each satellite control room 230. Theclient computer 220 can thereby send control signals to the diagnosticsystem over the data network. In the case where two users attempt toassert control of the system at the same time, the server 135 may assignpriority to the user who began the procedure first or who is at a morecritical phase of the procedure, such as actively acquiring OCT or IVUSor FFR data.

In addition to OCT and ultrasound images, angiographic X-ray imagestypically provide planar visualizations of vascular morphology over alarge field of view. OCT and ultrasound images typically providecross-sectional visualizations or three-dimensional renderings ofvascular microstructure in a single blood vessel over a pullbackdistance of about 5-about 15 cm. Because interventional procedures suchas stent implantation are guided in real time under angiography alone,it is desirable to precisely co-register the large field of view,low-resolution angiography images with the small field of view,high-resolution OCT or ultrasound images. This provides the physicianwith both contextual data about the overall vascular map andcross-sectional detailed data about the target lesion.

As described above, the multimodal diagnostic system is capable ofretrieving previously acquired angiography images by interfacing to adata network that is also connected to an angiographic X-ray system orby interfacing directly with the angiographic X-ray system. The datanetwork may be for example a network associated with a facilityoperating a catheterization lab or a hospital. These angiography imagesmay be acquired at the same time as a set of OCT or ultrasound imagesthat are stored on the server 135. Simultaneous acquisition ofangiography images and OCT or ultrasound images is feasible with the useof a radiopaque contrast fluid flush during invasive OCT or ultrasoundimaging. A software algorithm executing on the server 135 or anothercomponent of the data collection system can be used to spatiallyco-register the angiography and the OCT or ultrasound data.

The hardware used to handle transmission of collected patient image dataand to interface between different data collection systems or modulesthereof can be configured in various ways. For example, softwareconfigured to process differ types of image data such as to co-registerangiography and OCT and/or ultrasound data can receive data from thedifferent components described herein. In one embodiment, optical datagenerated using OCT and acoustic data generated using IVUS can becombined individually or collectively with angiography data generatedusing x-rays wherein each of these three types of data are transmittedover one or more networks. Ultrasound data and angiography data can betransformed into optical signals and transmitted over one or morelengths of optical fibers used in some of the data collection systemsdescribed herein. As a result, in one embodiment, the invention relatesto collecting a plurality of sets of image data using different imagingmodalities and transmitting them over a network. This network orindividual optical or electronic transmission paths can be integrated aspart of a data collection system over one or more optical fibers inoptical communication with a sample arm and/or a reference arm of aninterferometer.

FIGS. 10A and 10B show an ultrasound image of a fixed human coronaryartery and an OCT image of a living human finger pad, respectively. Theultrasound image of FIG. 10A was acquired at a speed of 50,000 imagelines per second and 100 frames per second, and was transmitted from areceiver to a digitizer board over a 15 meter single-mode optical fiberlink. The OCT image of FIG. 10B was acquired at a speed of 100,000 imagelines per second and 100 frames per second using the interferometerdesign described above. Sample arm and reference arm light wastransmitted from the imaging engine to the PIU dock over 30 metersingle-mode optical fiber links. Thus, it is possible and oftendesirable to separate certain components of a data collection system ora multimodal system using optical fiber links in various embodiments ofthe invention. Given the expense and size associated with a digitizerand the associated housing and controls that may be associated with thesame, having a digitizer in one room such that it receives data from oneor more procedure rooms is more efficient than having a digitizer ineach room. The same can be said of the imaging engine and othercomponents of a given data collection system described herein.

Accordingly, the angiography, OCT, and ultrasound data may be displayedtogether on the same monitor, and a marker may be placed on imagesformed from one modality to indicate the position of images formed fromthe other modality. For example, a marker may be placed on a 2D planarangiography image to indicate the position of a 2D cross-sectional OCTimage acquired as part of a longer OCT pullback. This enables theoperator to precisely assess on angiography the location ofintravascular features visible only under OCT or IVUS. In this way,precise guidance of interventional procedures such as stent implantationis made possible.

In addition, embodiments of the invention relate to methods, systems,and devices that are suitable for efficiently allocating components ofan OCT, IVUS, FFR or a multimodal system that combine two of theforegoing or other modalities into a system positioned at specific orgeneral spatial coordinates relative to other components, devices orsubsystems in a catheterization laboratory or cath lab or other medicalfacility. Thus, for example, in the context of an OCT system, a lightsource such as a swept laser, a digitizer, optical delay lines or fiberloops, interferometers and components thereof such as sample arms andreference arms, consoles, electrical subsystems and clock generators,housings for the foregoing and other items may be in optical orelectrical communication with each other. Given that several of theseconstituents of an OCT system are bulky, expensive, fragile, sensitiveto vibration or interference and/or possibly each of the foregoing, itis desirable to develop arrangements of such primary components orconstituent elements that avoid unnecessary duplication, inefficiency,and reduced data quality.

In light of the foregoing, it is also worth noting that in many OCT,IVUS, and/or FFR data collection sessions; the procedure room in whichthe data is collected is adjacent to a dedicated control room. In oneembodiment, individual carts or installations of an OCT system thatinclude all of the necessary optical and electrical components can beused in a given procedure room. However, given the points raised above,a one-to-many topology that segregates some of the more expensive,heavier or bulky components as primary components from other parts ofthe system, secondary or 2^(nd) components, can reduce costs by havingonly one of each of the expensive, bulky, or delicate componentsconnected to many procedure rooms.

Thus, in one embodiment, a first data collection system such as an OCT,an IVUS, and/or a FFR system or a system that combines two or more ofthe foregoing can be configured such that its components are connectedto form one or more networks. These configurations can be used tosupport the co-registration and transmission of ultrasound data orangiographic data along an optical fiber following a transformation fromthe format that the data was first collected, such as an acoustic signalor an electrical signal. Alternatively, electrical signal-based networksor sub-networks in communication with optical networks can be used.Various components of a data collection system such as a digitizer, alight source, a housing, or other OCT, IVUS, or FFR components can beidentified as a principal component or node in a network that is eitherin electrical communication, optical communication, or both with asecondary OCT, IVUS, or FFR system component or a plurality of other orsecondary OCT, IVUS, or FFR system components. The use of the termsprimary and secondary is general and the various data collection systemsand components thereof can be used without limitation regarding any ofthe components described herein. Examples of this are shown in FIGS.11A-11C in which a primary component is electrically and/or opticallycoupled with a secondary component identified as “2^(nd).” Thus, in oneembodiment, a digitizer and/or a light source or server can be a primarycomponent that is at a first location.

As a result, the primary component is in electrical and/or opticalcommunication with one or more secondary components. The primary andsecondary components can include, without limitation, an OCT probe orpart of the sample arm, pressure probe, wireless receiver, wirelesstransmitter, electro-optical signal converter, or other components. Inturn, primary and secondary components can be positioned at differentdistances or different locations relative to each other. For example,these components can be positioned such that they are remote or proximalrelative to a location such as a bed or as other location in a room. Inone embodiment, components can be in the same room but still be remotefrom each other although linked by a length of optical fiber, anelectrical wire or wireless connection. Thus, a patient can be restingon a support such as a bed during a data collection procedure such that,in one embodiment, the probe inserted in the patient's artery is acombination OCT and IVUS probe. The IVUS data can be generatedacoustically and transmitted wirelessly to a receiver before beingtransmitted in an optical format following a transformation with anelectro-optical converter. The optical OCT data and the IVUS data can beprocessed at a server to create a three-dimensional image orco-registered with angiography data or various other uses. These varioussteps and the devices used at each stage are configured to form anetwork of data processing and routing such that multi-room and remotein-room data collection and processing can be performed.

In one embodiment, the principal OCT component and the one or moresecondary OCT components are in different rooms such as a control roomor a procedure room. In one embodiment, the network topology by whichthe principal OCT component is in communication with one or moresecondary OCT components can include, without limitation, a startopology, an extended star topology, a bus topology, a hierarchicaltopology, and other topologies that improve the cost to benefit ratio orsignal to noise ratio for one or more OCT data collection sessions,either alone or in the aggregate.

Wireless Control Device

In one embodiment, the invention relates to an input device orcontroller configured to move in three-dimensions and control or displaydata collected with respect to a sample using one of the systems,devices or probes described herein. The input device or controller canbe implemented as a mouse such as a tableside mouse, or a joystick suchas a tableside joystick. A multimodal system 420, which has severalelements in common with the embodiment of FIG. 1C include a mobileterminal 425 and various related mobile or wireless components. Thebottom right quadrant of FIG. 12 shows such a controller or inputdevice. The input device can translate a rotation or turn of the deviceinto a wireless signal that can control what is displayed on a screen orremote terminal.

In one embodiment, the input device is a mouse or joystick such as themouse shown in FIG. 12. Thus, in a mouse or joystick configuration, theinput device is a pointing-and-clicking device that can be used in twomodes. In the first mode, it is used as a wireless mouse or joystick inconjunction with a mouse tray or joystick enclosure box mounted to thebedside rail or another surface. In this mode, an optical sensor on thebottom of the mouse is used to track motion over the mouse tray, or asensor or set of sensors in the joystick is used to track angularmotion. The input device may be placed in a disposable sterile bag toprevent contamination, or the entire input device and tray may be drapedin a sterile sheet for the same purpose.

In the second mode, the input device may be picked up off the mouse trayor other surface and used as a free-space pointer. The input deviceincorporates a set of gyroscopes or accelerometers to track motion infree space without requiring the use of a tray. Again, the input devicemay be placed in a disposable sterile bag to prevent contamination.

In both modes of operation, position data from the tableside mouse orjoystick is transmitted to a first wireless transceiver located in a PIUdock that is also mounted to the patient table. The receiver can be awireless USB dongle, and can be connected to a USB hub inside the PIUdock. A single USB connection to the server PC allows mouse commands tobe implemented on the data collection system software. This USBconnection may be a USB cable or an extended-length cable, depending onthe distance between the PIU dock and the server PC. When the linklength extends beyond several meters, an optical USB link may be used toprevent signal degradation and eliminate RF interference.

The mouse or joystick can be used by a clinician to control the datacollection system or other components in electrical or opticalcommunication therewith. Information from the data collection system,such as the systems in FIGS. 1A-1C, is displayed on an output device.The output devices can be a monitor mounted to a ceiling boom adjacentto the patient table. Other output device and/or related displays orinterface subsystems suitable for use with input device are shown inFIGS. 15-17. The clinician may therefore be up to several meters awayfrom the monitor or other output device while using the input device,such as a tableside mouse or joystick to operate the data collectionsystem. For this reason, the graphical user interface (GUI) on the datacollection system is modified with larger control buttons, dialog boxes,and text sizes. This GUI modification reduces the precision requiredfrom the mouse or joystick, making free-space pointer operationpractical with a distant monitor.

In one embodiment, the input device can be translated in one directionto move along the path of a vessel rendered as a two-dimensional orthree-dimensional tomographic image associated with an OCT datacollection session such as a pullback. In one embodiment, rotating orotherwise translating the input device can cause a rotation of the 2D or3D image of a vessel or components thereof. Pitch, yaw, angularposition, x, y, and z positions can also be used to track movement ofthe input device wherein such movement causes images or other data to bedisplayed based on OCT, FFR, X-ray and other data for a given sample orpatient of interest.

Mobile Terminal

In some situations, users prefer to control the data collection systemfrom a location other than the patient bed or the control room. FIG. 12shows an exemplary mobile terminal embodiment in the bottom rightquadrant. A technician may, for example, prefer to control dataacquisition and perform data review from a terminal in the procedureroom. A mobile terminal using wireless communication addresses thisneed. The mobile terminal includes a wireless video receiver, monitor,wireless keyboard, and wireless mouse to control the data collectionsystem or system in electrical or optical communication with it. Theterminal can be mounted on a wheeled cart to allow it to be positionedanywhere in the procedure room. Other mobile devices can be used.

The wireless keyboard and mouse in the mobile terminal are incommunication with a second wireless transceiver located in the PIUdock. This transceiver is connected to the same digital hub as the firstwireless transceiver. The monitor on the mobile terminal receives videodata from a wireless video receiver. This receiver is in communicationwith a wireless video transmitter connected to the server PC. Thetransmitter can be mounted in a location in or near the control roomthat allows the video signal to pass to the receiver without beingaffected by the radiation shielding commonly used in control room wallsand windows.

In one embodiment, the data collection systems described herein includesa wired/wireless architecture that includes wired/wireless probes andcontrol points. In addition, in one embodiment, the invention includes awired/wireless touch screen control panel that can be used to operate adata collection system. The touch panel can include image display andinterface functions. The mobile terminal can be configured to work inconjunction with a controller that transforms movements inthree-dimensions to change an output on a display.

Medical Devices/Probes, Methods, and Other Features

One or more pressure probes can be used with the multimodal systemdescribed herein. These probes can include a pressure sensor ortransducer that receives electrical power. To power a sensor positionedon or near a guidewire and to communicate signals representing ameasured physiological variable to a control unit acting as an interfacedevice disposed outside the body, one or more cables for transmittingthe signals are connected to the sensor, and are routed along the guidewire to be passed out from the vessel to an external control unit via aconnector assembly. The control unit may be adapted to convert sensorsignals into a format accepted by the ANSI/AAMI BP22-1994. In addition,the guide wire is typically provided with a central metal wire (corewire) serving as a support for the sensor.

FIG. 13 shows a probe embodiment 801. The probe 801 includes a sensorand a guide wire. The probe has, in the drawing, been divided into fivesections, 802-806, for illustrative purposes. The section 802 is themost distal portion, i.e. that portion which is going to be insertedfarthest into the vessel, and section 806 is the most proximal portion,i.e. that portion being situated closest to a not shown control unit.Section 802 can include a radiopaque coil 808 made of e.g. platinum,provided with an arced tip 807. In the platinum coil and the tip, thereis also attached a stainless, solid metal wire 809, which in section 802is formed like a thin conical tip and functions as a security thread forthe platinum coil 808. The successive tapering of the metal wire 809 insection 802 towards the arced tip 807 results in that the front portionof the sensor guide construction becomes successively softer.

At the transition between the sections 802 and 803, the lower end of thecoil 808 is attached to the wire 809 with glue or alternatively, solder,thereby forming a joint 118. At the joint 118 a thin outer tube 811commences which is made of a biocompatible material, e.g. polyimide, andextends downwards all the way to section 806. The tube 811 can betreated to give the sensor guide construction a smooth outer surfacewith low friction. The metal wire 809 is heavily expanded in section 803and is in this expansion provided with a slot 812 in which a sensorelement 814 is arranged, e.g. a pressure gauge. The sensor requireselectric energy for its operation. The expansion of the metal wire 809in which the sensor element 814 is attached decreases the stress exertedon the sensor element 814 in sharp vessel bends.

From the sensor element 814 there is arranged a signal transmittingcable 816, which typically can include one or more electric cables. Thesignal transmitting cable 816 extends from the sensor element 814 to an(not shown) interface device being situated below the section 806 andoutside the body. A supply voltage is fed to the sensor via thetransmitting cable 816 (or cables). The signals representing themeasured physiological variable are also transferred along thetransmitting cable 816. The metal wire 809 is substantially thinner inthe beginning of section 804 to obtain good flexibility of the frontportion of the sensor guide construction. At the end of section 804 andin the whole of section 805, the metal wire 809 is thicker in order tomake it easier to push the sensor guide construction 801 forward in thevessel. In section 806 the metal wire 809 is as coarse as possible to beeasy to handle and can include with a slot 820 in which the cable 816 isattached with e.g. glue.

The use of a guide wire 201, such as is illustrated in FIG. 13, isschematically shown in FIG. 14. Guide wire 201 is inserted into thefemoral artery of a patient 225. The position of guide wire 201 and thesensor 214 inside the body is illustrated with dotted lines. Guide wire201, and more specifically electrically transmitting cable 211 thereof,is also coupled to a control unit 222 via a wire 226 that is connectedto cable 211 using any suitable connector element or subsystem (notshown), such as a crocodile clip-type connector or any other knownconnector. The wire 226 is preferably made as short as possible foreasiness in handling the guide wire 201. Preferably, the wire 226 isomitted, such that the control unit 222 is directly attached to thecable 211 via suitable connectors. The control unit 222 provides anelectrical voltage to the circuit that includes wire 226, cable 211 ofthe guide wire 201 and the sensor 214. Moreover, the signal representingthe measured physiological variable is transferred from the sensor 214via the cable 211 to the control unit 222. The method to introduce theguide wire 201 is well known to those skilled in the art.

From the control unit 222, a signal representing distal pressuremeasured by the sensor 214 is communicated to one or more monitordevices, preferably using the ANSFAAMI BP22-1994, either by means ofwireless communication or via a wired connection. This information canbe transmitted to one or more wireless pressure receivers such asreceivers 129 and 130 of FIG. 1B.

The voltage provided to the sensor by the control unit could be an AC ora DC voltage. Generally, in the case of applying an AC voltage, thesensor is typically connected to a circuit that includes a rectifierthat transforms the AC voltage to a DC voltage for driving the sensorselected to be sensitive to the physical parameter to be investigated.

FIG. 15 illustrates a data collection system 850 configured to use amedical device or probe, which can include a pressure or imagingcomponent or subsystem for monitoring, analysing, and/or displayingphysiological conditions or image data from within a body. Thephysiological conditions can include FFR, OCT image data, bloodpressure, and other data collected using a probe or the systems of FIGS.1A-1C.

The data collection system 850 can include a pressure wire receiver unit852 configured to receive a wireless signal representing a measuredphysiological, or other, variable in the living body, an aortic bloodpressure receiver unit 853 configured to receive, from at least oneaortic pressure interface unit (not shown), a wireless signal includinginterface identity information required to identify the interface unit,and information representing measured aortic blood pressure. The system850 can include a signal processing element or subsystem 854 configuredto calculate blood pressure related parameters.

The system 850 can also include a touch screen 855 configured to displayinformation regarding selectable aortic pressure interface units,pressure wire interface units, and blood pressure related parameters,FFR values, and OCT generated images, and to receive user input. Inaddition, the system 850 and an identifying unit 856 can be configuredto identify interface units based upon received interface identityinformation, and a presentation unit 857 configured to present, on thetouch screen 855, the interface unit(s) identified by the identifyingunit 856. Furthermore, the system 850 can include selecting unit 858configured to select one of the presented interface units. In oneembodiment, the aortic blood pressure receiver unit 853 is configured toreceive aortic pressure information from a selected aortic pressureinterface unit. The touch screen 855 can include a graphic userinterface suitable for selecting between rooms and data collectionsprobes in the embodiments shown in FIGS. 1A-1C.

According to another embodiment of the invention, as shown in FIG. 15 bythe dotted element, the probe 850 can further include a matching unit859 that is configured to match identified interface units with a set ofstored interface unit identities, and wherein the presentation unit 857is configured to present, on the touch screen 855, the interface unit(s)having a positive match. In one embodiment, the selection by theselecting unit 858 is made in response of a user input on the touchscreen 855. A pressure probe or pressure data receiver can haveassociated interface units configured to send data. The interface unitscan be probe interface units or interfaces or devices configured totransmit a particular type of data such as OCT, pressure, ultrasound,control signals, or other data.

In another embodiment, the selection by the selecting unit 858 is madeautomatically according to predetermined selecting rules. Thepredetermined selecting rules may include parameters related to thereceived wireless signal. For example, the predetermined selecting rulesmay include signal strength or an optical beam parameter. Accordingly,the selection by the selecting unit may be made by selecting theinterface unit that has generated the wireless signal having the highestsignal/noise ratio. The selection rule can also be reception of atrigger signal indicating which procedure room has a patient ready foran OCT pullback and image data collection event.

In one embodiment, the aortic blood pressure receiver unit 853 isconfigured to receive calibration data related to the selected aorticpressure interface unit. According to one embodiment, the pressure wirereceiver unit 852 and/or the aortic blood pressure receiver unit 853 aredetachable. In one embodiment, the pressure wire receiver unit isconnectable to the device via a USB connection. In one embodiment, theaortic blood pressure receiver unit 853 is connectable to the device 850via a USB connection or a wireless connection.

According to a further aspect, the invention relates to a medical systemfor monitoring, analysing, and displaying physiological conditionsrelated to blood pressure within a living body, the system includes aprobe, which can include a pressure or imaging probe. According to oneembodiment of the invention, as illustrated in FIG. 16, the system formonitoring, analysing, and displaying physiological conditions or otherdata includes a display. As shown, the display of FIG. 16 can be fixedor mobile. A user interface and various inputs are included in thedisplay device as shown. In one embodiment, the screen is a touchscreen. Various data feeds or sources of physiological conditions orother data A, B, and C are shown. These can be any of the data generatedor resulting from the processing of data generated by a data collectionsystem such as those shown in FIGS. 1A-1C.

In turn, FIG. 17 shows a patient P to the left and a remote server ordata collection S or processing system to the right. The patient P canbe connected to various monitors or receivers (generally M) that collectlocal data such as blood pressure, oxygen levels, and others and relaysuch collected local data to one or more devices using a network deviceN having a wired connection, wireless or other connection. This data canbe collected during an OCT or other catheter based procedure. In turn,once this data is captured, it can be wirelessly relayed to a display ora remote server or processing system S as shown. A handheld device ortouchscreen monitor having a graphic user interface (GUI) can be used tocontrol the system or collect data therefrom.

One embodiment of the invention can include one aortic pressureinterface unit configured to receive information representing measuredaortic blood pressure, and to transmit a wireless signal includinginterface identity information required to identify the interface unit,and information representing the measured aortic blood pressure.

One embodiment of the invention relates to a network of elements havingelectrical and optical inputs and outputs such that a mixed optical andelectrical network of nodes and links results. In one embodiment, a linkbetween two nodes that include either a principal OCT component and/or asecondary OCT component includes an arm of an interferometer such as asample arm or a reference arm of an interferometer or a portion thereof.

The aspects, embodiments, features, and examples of the invention are tobe considered illustrative in all respects and are not intended to limitthe invention, the scope of which is defined only by the claims. Otherembodiments, modifications, and usages will be apparent to those skilledin the art without departing from the spirit and scope of the claimedinvention.

The use of headings and sections in the application is not meant tolimit the invention; each section can apply to any aspect, embodiment,or feature of the invention.

Throughout the application, where compositions are described as having,including, or comprising specific components, or where processes aredescribed as having, including or comprising specific process steps, itis contemplated that compositions of the present teachings also consistessentially of, or consist of, the recited components, and that theprocesses of the present teachings also consist essentially of, orconsist of, the recited process steps.

In the application, where an element or component is said to be includedin and/or selected from a list of recited elements or components, itshould be understood that the element or component can be any one of therecited elements or components and can be selected from a groupconsisting of two or more of the recited elements or components.Further, it should be understood that elements and/or features of acomposition, an apparatus, or a method described herein can be combinedin a variety of ways without departing from the spirit and scope of thepresent teachings, whether explicit or implicit herein.

The use of the terms “include,” “includes,” “including,” “have,” “has,”or “having” should be generally understood as open-ended andnon-limiting unless specifically stated otherwise.

The use of the singular herein includes the plural (and vice versa)unless specifically stated otherwise. Moreover, the singular forms “a,”“an,” and “the” include plural forms unless the context clearly dictatesotherwise. In addition, where the use of the term “about” is before aquantitative value, the present teachings also include the specificquantitative value itself, unless specifically stated otherwise.

It should be understood that the order of steps or order for performingcertain actions is immaterial so long as the present teachings remainoperable. Moreover, two or more steps or actions may be conductedsimultaneously.

Where a range or list of values is provided, each intervening valuebetween the upper and lower limits of that range or list of values isindividually contemplated and is encompassed within the invention as ifeach value were specifically enumerated herein. In addition, smallerranges between and including the upper and lower limits of a given rangeare contemplated and encompassed within the invention. The listing ofexemplary values or ranges is not a disclaimer of other values or rangesbetween and including the upper and lower limits of a given range.

The terms light and electromagnetic radiation are used interchangeablyherein such that each term includes all wavelength (and frequency)ranges and individual wavelengths (and frequencies) in theelectromagnetic spectrum. Similarly, the terms device and apparatus arealso used interchangeably. In part, embodiments of the invention relateto or include, without limitation: sources of electromagnetic radiationand components thereof; systems, subsystems, and apparatuses thatinclude such sources; mechanical, optical, electrical and other suitabledevices that can be used as part of or in communication with theforegoing; and methods relating to each of the forgoing. Accordingly, asource of electromagnetic radiation can include any apparatus, matter,system, or combination of devices that emits, re-emits, transmits,radiates or otherwise generates light of one or more wavelengths orfrequencies.

One example of a source of electromagnetic radiation is a laser. A laseris a device or system that produces or amplifies light by the process ofstimulated emission of radiation. Although the types and variations inlaser design are too extensive to recite and continue to evolve, somenon-limiting examples of lasers suitable for use in embodiments of theinvention can include tunable lasers (sometimes referred to as sweptsource lasers), superluminescent diodes, laser diodes, semiconductorlasers, mode-locked lasers, gas lasers, fiber lasers, solid-statelasers, waveguide lasers, laser amplifiers (sometimes referred to asoptical amplifiers), laser oscillators, and amplified spontaneousemission lasers (sometimes referred to as mirrorless lasers orsuperradiant lasers).

Non-Limiting Software Embodiments for Multimodal Methods and Apparatus

The present invention may be embodied in many different forms,including, but in no way limited to, computer program logic for use witha processor (e.g., a microprocessor, microcontroller, digital signalprocessor, or general purpose computer), programmable logic for use witha programmable logic device, (e.g., a Field Programmable Gate Array(FPGA) or other PLD), discrete components, integrated circuitry (e.g.,an Application Specific Integrated Circuit (ASIC)), or any other meansincluding any combination thereof. In one embodiment of the presentinvention, some or all of the processing of the data collected using anOCT probe, ultrasound probe, FFR device, or other data collectionmodality is implemented as a set of computer program instructions thatis converted into a computer executable form, stored as such in acomputer readable medium, and executed by a microprocessor under thecontrol of an operating system. Control and operation of components of agiven component, system, subsystem, or apparatus can also be socontrolled or operated using a computer. In one embodiment, light,radiofrequency, electrical and other signals or other data aretransformed into processor understandable instructions suitable forcollecting data from one or more modalities, triggering data collectionor other clocking events, synchronizing data collection, transmittingdata between one or more locations such as different rooms, and otherfeatures and embodiments as described above.

Computer program logic implementing all or part of the functionalitypreviously described herein may be embodied in various forms, including,but in no way limited to, a source code form, a computer executableform, and various intermediate forms (e.g., forms generated by anassembler, compiler, linker, or locator). Source code may include aseries of computer program instructions implemented in any of variousprogramming languages (e.g., an object code, an assembly language, or ahigh-level language such as Fortran, C, C++, JAVA, or HTML) for use withvarious operating systems or operating environments. The source code maydefine and use various data structures and communication messages. Thesource code may be in a computer executable form (e.g., via aninterpreter), or the source code may be converted (e.g., via atranslator, assembler, or compiler) into a computer executable form.

The computer program may be fixed in any form (e.g., source code form,computer executable form, or an intermediate form) either permanently ortransitorily in a tangible storage medium, such as a semiconductormemory device (e.g., a RAM, ROM, PROM, EEPROM, or Flash-ProgrammableRAM), a magnetic memory device (e.g., a diskette or fixed disk), anoptical memory device (e.g., a CD-ROM), a PC card (e.g., PCMCIA card),or other memory device. The computer program may be fixed in any form ina signal that is transmittable to a computer using any of variouscommunication technologies, including, but in no way limited to, analogtechnologies, digital technologies, optical technologies, wirelesstechnologies networking technologies, and internetworking technologies.The computer program may be distributed in any form as a removablestorage medium with accompanying printed or electronic documentation(e.g., shrink-wrapped software), preloaded with a computer system (e.g.,on system ROM or fixed disk), or distributed over a network.

Programmable logic may be fixed either permanently or transitorily in atangible storage medium, such as a semiconductor memory device (e.g., aRAM, ROM, PROM, EEPROM, or Flash-Programmable RAM), a magnetic memorydevice (e.g., a diskette or fixed disk), an optical memory device (e.g.,a CD-ROM), or other memory device. The programmable logic may be fixedin a signal that is transmittable to a computer using any of variouscommunication technologies, including, but in no way limited to, analogtechnologies, digital technologies, optical technologies, wirelesstechnologies (e.g., Bluetooth), networking technologies, andinternetworking technologies. The programmable logic may be distributedas a removable storage medium with accompanying printed or electronicdocumentation (e.g., shrink-wrapped software), preloaded with a computersystem (e.g., on system ROM or fixed disk), or distributed from a serveror electronic bulletin board over the communication system (e.g., theInternet or World Wide Web).

Various examples of suitable processing modules are discussed below inmore detail. As used herein a module refers to software, hardware, orfirmware suitable for performing a specific data processing or datatransmission task. Typically, in a preferred embodiment a module refersto a software routine, program, or other memory resident applicationsuitable for receiving, transforming, registering, co-registering,routing and processing instructions, or various types of data such asOCT scan data, ultrasound data, FFR data, interferometer signal data,clocks, radiofrequency data, and other information or data of interest.

Servers, computers and computer systems described herein may includeoperatively associated computer-readable media such as memory forstoring software applications used in obtaining, processing, storingand/or communicating data. It can be appreciated that such memory can beinternal, external, remote or local with respect to its operativelyassociated computer or computer system.

Memory may also include any means for storing software or otherinstructions including, for example and without limitation, a hard disk,an optical disk, floppy disk, DVD (digital versatile disc), CD (compactdisc), memory stick, flash memory, ROM (read only memory), RAM (randomaccess memory), DRAM (dynamic random access memory), PROM (programmableROM), EEPROM (extended erasable PROM), and/or other likecomputer-readable media.

In general, computer-readable memory media applied in association withembodiments of the invention described herein may include any memorymedium capable of storing instructions executed by a programmableapparatus. Where applicable, method steps described herein may beembodied or executed as instructions stored on a computer-readablememory medium or memory media.

It is to be understood that the figures and descriptions of theinvention have been simplified to illustrate elements that are relevantfor a clear understanding of the invention, while eliminating, forpurposes of clarity, other elements. Those of ordinary skill in the artwill recognize, however, that these and other elements may be desirable.However, because such elements are well known in the art, and becausethey do not facilitate a better understanding of the invention, adiscussion of such elements is not provided herein. It should beappreciated that the figures are presented for illustrative purposes andnot as construction drawings. Omitted details and modifications oralternative embodiments are within the purview of persons of ordinaryskill in the art.

It can be appreciated that, in certain aspects of the invention, asingle component may be replaced by multiple components, and multiplecomponents may be replaced by a single component, to provide an elementor structure or to perform a given function or functions. Except wheresuch substitution would not be operative to practice certain embodimentsof the invention, such substitution is considered within the scope ofthe invention.

The examples presented herein are intended to illustrate potential andspecific implementations of the invention. It can be appreciated thatthe examples are intended primarily for purposes of illustration of theinvention for those skilled in the art. There may be variations to thesediagrams or the operations described herein without departing from thespirit of the invention. For instance, in certain cases, method steps oroperations may be performed or executed in differing order, oroperations may be added, deleted or modified.

Furthermore, whereas particular embodiments of the invention have beendescribed herein for the purpose of illustrating the invention and notfor the purpose of limiting the same, it will be appreciated by those ofordinary skill in the art that numerous variations of the details,materials and arrangement of elements, steps, structures, and/or partsmay be made within the principle and scope of the invention withoutdeparting from the invention as described in the claims.

What is claimed is:
 1. An intravascular data collection systemcomprising: a server comprising: a first input to receive intravascularimaging data; a second input to receive intravascular data; a thirdinput to receive patient data; one or more processors to executeinstructions with regard to the intravascular imaging data,intravascular data and patient data; one or more electronic memorystorage devices to store the intravascular imaging data, intravasculardata and patient data; an intravascular imaging system comprising animaging engine having a light source, the intravascular imaging systembeing in communication with the first input; a first patient interfaceunit positioned in a first procedure room in which patient imaging isperformed; a first patient interface unit dock arranged as an interfacebetween the first patient interface unit, the intravascular imagingsystem and the server, the first patient interface unit dock beingpositioned in the first procedure room and configured to mechanicallymount the first patient interface unit when the first patient interfaceunit is not in use; a second patient interface unit positioned in asecond procedure room in which patient imaging is performed; and asecond patient interface unit dock arranged as an interface between thesecond patient interface unit, the intravascular imaging system and theserver, the second patient interface unit dock being positioned in thesecond procedure room and configured to mechanically mount the secondpatient interface unit when the second patient interface unit is not inuse, wherein the intravascular imaging engine and the server arepositioned in a room different than the first procedure room and thesecond procedure room.
 2. The system of claim 1 wherein the patient datais angiography data.
 3. The system of claim 2 wherein the intravasculardata is pressure data.
 4. The system of claim 3 further comprising ahub, wherein the second input receives the pressure data from the hub.5. The system of claim 3 further comprising instructions stored in theone or more electronic memory devices to co-register intravascularimaging data with the pressure data, the angiography data or both. 6.The system of claim 2 wherein the third input receives angiography datafrom a hub.
 7. The system of claim 1 wherein the intravascular data isaortic pressure data.
 8. The system of claim 1 wherein the serverfurther comprises a digitizer, wherein the digitizer is in communicationwith the imaging engine.
 9. The system of claim 8 further comprising aclock generator, wherein the digitizer comprises two channels, whereinat least one channel of the two channels is configured to acquire dataaccording to a variable frequency external clock from the clockgenerator.
 10. The system of claim 1 wherein the server is incommunication with one or more user interface devices.
 11. The system ofclaim 10 wherein the one or more user interface devices are selectedfrom the group consisting of a monitor, a touch screen, a mouse, akeyboard and a joystick.
 12. The system of claim 1 wherein theintravascular imaging system comprises an ultrasound system.
 13. Thesystem of claim 12 wherein the ultrasound system comprises an ultrasoundswitch.
 14. The system of claim 1 wherein the imaging engine comprisesan interferometer, the interferometer comprising a reference arm, asample arm and a variable path length mirror, wherein the reference armcomprise a first optical fiber segment and the sample arm comprises asecond optical fiber segment, wherein the imaging engine directs lightreceived in the reference arm through the variable path length mirror tomatch distance traveled by the light received in the sample arm.
 15. Thesystem of claim 1 further comprising a video switch and a plurality ofmonitors, the video switch in electrical communication with the serverand the plurality of monitors.
 16. The system of claim 1 wherein theintravascular imaging system comprises an ultrasound system including atransducer, a receiver and a switch, and wherein the ultrasound systemis configured to perform one or more of the following: generateultrasound pulses, using a transducer; receive ultrasound signalsreturned from a sample using the receiver; and transition betweentransmit mode and receive mode using the switch.
 17. The system of claim1 further comprising a user interface device, wherein the user interfacedevices comprises a touch screen device in communication with theserver, the intravascular imaging system, or both.
 18. The system of 17,wherein the touch screen device is configured to receive user inputs andto display information to a user selected from the group consisting theintravascular data, pressure data, and blood pressure relatedparameters, fractional flow reserve values, optical coherence tomographygenerated images, selectable aortic pressure interface units, andpressure sensing interface units.
 19. The system of claim 1, wherein theintravascular imaging system comprises a first imaging modalityincluding an optical imaging modality.
 20. The system of claim 19,wherein the intravascular imaging system comprises a second imagingmodality that is not an optical imaging modality.